Ultrathin Anatase TiO2Nanosheets Embedded with TiO2-B Nanodomains for Lithium-Ion Storage: Capacity Enhancement by Phase Boundaries

Monolithic Microparticles Facilitated Flower-Like TiO2 Nanowires for High Areal Capacity Flexible Li-Ion Batteries

Flexible lithium-ion batteries (FLIBs) are intensively studied using free-standing transition metal oxides (TMOs)-based anode materials. However, achieving high areal capacity TMO-based anode materials is yet to be effectively elucidated owing to the poor adhesion of the active materials to the flexible substrate resulting in low active mass loading, and hence low areal capacity is realized. Herein, a novel monolithic rutile TiO2 microparticles on carbon cloth (ATO/CC) that facilitate the flower-like arrangement of TiO2 nanowires (denoted ATO/CC/OTO) is demonstrated as high areal capacity anode for FLIBs. The optimized ATO/CC/OTO anode exhibits high areal capacity (5.02 mAh cm-2@0.4 mA cm-2) excellent rate capability (1.17 mAh cm-2@5.0 mA cm-2) and remarkable cyclic stability (over 500 cycles). A series of morphological, kinetic, electrochemical, in situ Raman, and theoretical analyses reveal that the rational phase boundaries between the microparticles and nanowires contribute to promoting the Li storage activity. Furthermore, a 16.0 cm2 all-FLIB pouch cell assembled based on the ATO/CC/OTO anode and LiNiCoMnO2 cathode coated on ATO/CC (ATO/CC/LNCM) exhibits impressive flexibility under different folding conditions, creating opportunity for the development of high areal capacity anodes in future flexible energy storage devices.

Simultaneous Enhancement of Lithium Transfer Kinetics and Structural Stability in Dual-Phase TiO2 Electrodes by Ruthenium Doping

Dual-phase TiO2 consisting of bronze and anatase phases is an attractive electrode material for fast-charging lithium-ion batteries due to the unique phase boundaries present. However, further enhancement of its lithium storage performance has been hindered by limited knowledge on the impact of cation doping as an efficient modification strategy. Here, the effects of Ru4+ doping on the dual-phase structure and the related lithium storage performance are demonstrated for the first time. Structural analysis reveals that an optimized doping ratio of Ru:Ti = 0.01:0.99 (1-RTO) is vital to maintain the dual-phase configuration because the further increment of Ru4+ fraction would compromise the crystallinity of the bronze phase. Various electrochemical tests and density functional theory calculations indicate that Ru4+ doping in 1-RTO enables more favorable lithium diffusion in the bulk for the bronze phase as compared to the undoped TiO2 (TO) counterpart, while lithium kinetics in the anatase phase are found to remain similar. Furthermore, Ru4+ doping leads to a better cycling stability for 1-RTO-based electrodes with a capacity retention of 82.1% after 1200 cycles at 8 C as compared to only 56.1% for TO-based electrodes. In situ X-ray diffraction reveals a reduced phase separation in the lithiated anatase phase, which is thought to stabilize the dual-phase architecture during extended cycling. The simultaneous enhancement of rate ability and cycling stability of dual-phase TiO2 enabled by Ru4+ doping provides a new strategy toward fast-charging lithium-ion batteries.

Facile preparation of urchin-like morphology V2O3-VN nano-heterojunction cathodes for high-performance Aqueous zinc ion battery

Rechargeable aqueous zinc ion batteries (RAZIBs) are of interest for energy storage in smart grids. However, slow Zn2+ diffusion kinetics, insufficient active sites, and poor intrinsic conductivity are always challenging to exploit the huge potential of the batteries. Here, we prepare V2O3-VN nano-heterojunction composites with sea urchin-like morphology as the cathode for AZIBs. The electrode achieves high capacities (e.g., 0.1 A g-1, 532.6 mAh g-1), good rate and cycle performance (263.4 mAh g-1 at 5 A g-1 current density with 90.8% capacity retention). Detailed structural analyses suggest that the V2O3-VN composite is composed of different crystal planes of V2O3 and VN, which form an efficient heterogeneous interfacial network in the bulk electrode, accounting for its good electrochemical properties. Theoretical calculations reveal that compared with V2O3, VN and physically mixed V2O3/VN, the V2O3-VN heterostructure exhibits good cation adsorption and electrode conductivity, thereby accelerating the charge carrier mobility and electrochemical activity of the electrode. Moreover, ex-situ characterization techniques are utilized to investigate the zinc storage mechanism in detail, providing new ideas for the development of AZIBs cathode materials through the construction of heterojunction structures.

A Branched Rutile/Anatase Phase Structure Electrode with Enhanced Electron-Hole Separation for High-Performance Photoelectrochemical DNA Biosensor

A photoelectrochemical (PEC) detection platform was built based on the branched rutile/anatase titanium dioxide (RA-TiO₂) electrode. Theoretical calculations proved that the type-II band alignment of rutile and anatase could facilitate charge separation in the electrode. The self-generated electric field at the interface of two phases can enhance the electron transfer efficiency of the electrode. Carboxylated CdTe quantum dots (QDs) were applied as signal amplification factors. Without the target DNA presence, the CdTe QDs were riveted to the surface of the electrode by the hairpin probe DNA. The sensitization of CdTe QDs increased the photocurrent of the electrode significantly. When the target DNA was present, the structural changes of the hairpin probe DNA resulted in the failure of the sensitized structure. Benefiting from excellent electrode structure design and CdTe QDs sensitization strategy, the PEC assays could achieve highly sensitive and specific detection of target DNA in the range of 1 fM to 1 nM, with a detection limit of 0.23 fM. The electrode construction method proposed in this article can open a new avenue for the preparation of more efficient PEC sensing devices.

Nanostructured TiO2 Arrays for Energy Storage

Because of their extensive specific surface area, excellent charge transfer rate, superior chemical stability, low cost, and Earth abundance, nanostructured titanium dioxide (TiO₂) arrays have been thoroughly explored during the past few decades. The synthesis methods for TiO₂ nanoarrays, which mainly include hydrothermal/solvothermal processes, vapor-based approaches, templated growth, and top-down fabrication techniques, are summarized, and the mechanisms are also discussed. In order to improve their electrochemical performance, several attempts have been conducted to produce TiO₂ nanoarrays with morphologies and sizes that show tremendous promise for energy storage. This paper provides an overview of current developments in the research of TiO₂ nanostructured arrays. Initially, the morphological engineering of TiO₂ materials is discussed, with an emphasis on the various synthetic techniques and associated chemical and physical characteristics. We then give a brief overview of the most recent uses of TiO₂ nanoarrays in the manufacture of batteries and supercapacitors. This paper also highlights the emerging tendencies and difficulties of TiO₂ nanoarrays in different applications.

Design of Bronze-Rich Dual-Phasic TiO2 Embedded Amorphous Carbon Nanocomposites Derived from Ti-Metal-Organic Frameworks for Improved Lithium-Ion Storage

Dual-phasic (DP)-TiO₂ -based composites are considered attractive anode materials for high lithium-ion storage because of the synergetic contribution from dual-phases in lithium-ion storage. However, a comprehensive investigation on more efficient architectures and platforms is necessary to develop lithium-storage devices with high-rate capability and long-term stability. Herein, for the first time, a rationally designed bronze-rich DP-TiO₂ -embedded amorphous carbon nanoarchitecture, denoted as DP-TiO₂ @C, from sacrificial Ti-metal-organic frameworks (Ti-MOFs) via a two-step pyrolysis process is proposed. The bronze/anatase DP-TiO₂ @C nanocomposites are successfully synthesized using a unique pyrolysis process, which decomposes individually the metal clusters and organic linkers of Ti-MOFs. DP-TiO₂ @C exhibits a significantly high density and even distribution of nanoparticles (<5 nm), enabling the formation of numerous heterointerfaces. Remarkably, the bronze-rich DP-TiO₂ @C shows high specific capacities of 638 and 194 mAh g^-1 at current densities of 0.1 and 5 A g^-1 , respectively, owing to the contribution of the synergetic interfacial structure. In addition, reversible specific capacities are observed at a high rate (5 A g^-1 ) during 6000 cycles. Thus, this study presents a new approach for the synthesis of DP-TiO₂ @C nanocomposites from a sacrificial Ti-MOF and provides insights into the efficient control of the volume ratio in DP-TiO₂ anode architecture.

High-Performance Mg-Li Hybrid Batteries Based on Pseudocapacitive Anatase Ti1-x Cox O2-y Nanosheet Cathodes

Despite the proposed safety, performance, and cost advantages, practical implementation of Mg-Li hybrid batteries is limited due to the unavailability of reliable cathodes compatible with the dual-ion system. Herein, a high-performance Mg-Li dual ion battery based upon cobalt-doped TiO₂ cathode was developed. Extremely pseudocapacitance-type Ti_1-x Co_x O_2-y nanosheets consist of an optimum 3.57 % Co-atoms. This defective cathode delivered exceptional pseudocapacitance (maximum of 93 %), specific capacities (386 mAh g^-1 at 25 mA g^-1 ), rate performance (191 mAh g^-1 at 1 A g^-1 ), cyclability (3000 cycles at 1 A g^-1 ), and coulombic efficiency (≈100 %) and fast charging (≈11 min). This performance was superior to the TiO₂ -based Mg-Li dual-ion battery cathodes reported earlier. Mechanistic studies revealed dual-ion intercalation pseudocapacitance with negligible structural changes. Excellent electrochemical performance of the cation-doped TiO₂ cathode was credited to the rapid pseudocapacitance-type Mg/Li-ion diffusion through the disorder generated by lattice distortions and oxygen vacancies. Ultrathin nature, large surface area, 2D morphology, and mesoporosity also contributed as secondary factors facilitating superior electrode-electrolyte interfacial kinetics. The demonstrated method of pseudocapacitance-type Mg-Li dual-ion intercalation by introducing lattice distortions/oxygen vacancies through selective doping can be utilized for the development of several other potential electrodes for high-performance Mg-Li dual-ion batteries.

Maximizing Performance of a Hybrid MnO2/Ni Electrochemical Actuator through Tailoring Lattice Tunnels and Cation Vacancies

Electrochemical actuators play a key role in converting electrical energy to mechanical energy. However, a low actuation stress and an unsatisfied strain response rate strongly limit the extensive applications of the actuators. Here, we report hybrid manganese dioxide (MnO₂) fabricated by introducing ramsdellite (R-MnO₂) and Mn vacancies into birnessite (δ-MnO₂) nanosheets, which in situ grew on the surface of a nickel (Ni) film, forming a hybrid MnO₂/Ni actuator. The actuator demonstrated a rapid strain response of 0.88% s^-1 (5.3% intrinsic strain in 6 s) and a large actuation stress of 244 MPa owing to the special R-MnO₂ with a high density of sodium ion (Na⁺)-accessible lattice tunnels, Mn vacancies, and also a high Young's modulus of the hybrid MnO₂/Ni composite. Besides, the cyclic stability of the actuator was realized after 1.2 × 10⁴ cycles of electric stimulation under a frequency of 0.05 Hz. The finding of the novel hybrid MnO₂/Ni actuator may provide a new strategy to maximize the actuating performance evidently through tailoring the lattice tunnel structure and introducing cation vacancies into electrochemical electrode materials.

Tuning the Defects of Two-Dimensional Layered Carbon/TiO2 Superlattice Composite for a Fast Lithium-Ion Storage

Defect engineering is one of the effective ways to improve the electrochemical property of electrode materials for lithium-ion batteries (LIB). Herein, an organic functional molecule of p-phenylenediamine is embedded into two-dimensional (2D) layered TiO₂ as the electrode for LIB. Then, the 2D carbon/TiO₂ composites with the tuning defects are prepared by precise control of the polymerization and carbothermal atmospheres. Low valence titanium in metal oxide and nitrogen-doped carbon nanosheets can be obtained in the carbon/TiO₂ composite under a carbonization treatment atmosphere of N₂/H₂ gas, which can not only increase the electronic conductivity of the material but also provide sufficient electrochemical active sites, thus producing an excellent rate capability and long-term cycle stability. The prepared composite can provide a high capacity of 396.0 mAh g⁻¹ at a current density of 0.1 A g⁻¹ with a high capacitive capacity ratio. Moreover, a high specific capacity of 80.0 mAh g⁻¹ with retention rate of 85% remains after 10,000 cycles at 3.0 A g⁻¹ as well as the Coulomb efficiency close to 100%. The good rate-capability and cycle-sustainability of the layered materials are ascribed to the increase of conductivity, the lithium-ion transport channel, and interfacial capacitance due to the multi-defect sites in the layered composite.

Eco-friendly utilization of sawdust: Ionic liquid-modified biochar for enhanced Li+ storage of TiO2

In China, forestry logging and wood processing produce hundreds of thousands of tons of sawdust every year, which is either discarded or burned. These nonecofriendly practices result in some challenges associated with greenhouse gas emissions. Sawdust-based biochar tailored for anodes of lithium-ion batteries (LIBs) can effectively realize value-added utilization of sawdust. The purpose of the current work is to prepare TiO₂/biochar nanocomposites to improve the electrical conductivity and structural stability of the anode. However, poor interfacial interaction between TiO₂ and carbon in the TiO₂/C composites arising from their heterogeneous nature leads to structural deformation of the composites used as anodes of lithium-ion batteries (LIBs). A strategy of constructing ionic liquid-coupled biochar/TiO₂ interfaces is proposed to obtain chemically bonded interfaces between TiO₂ and sawdust-derived biochar. In this study, TiO₂/C-880 composites are prepared by one-step carbonization of TiO₂ nanoparticles (NPs) and sawdust at 880 °C previously dissolved in 1-butyl-3-methyl-imidazolium ([Bmim]H₂PO₄)/dimethyl sulfoxide (DMSO). The morphologies of TiO₂/C-880 demonstrate that the TiO₂ is encapsulated by porous biochar with intimate interfaces, and the X-ray photoelectron spectroscopy (XPS) results indicate the formation of N-Ti-O/N-O-Ti and Ti-O-P bonds that bridge the two components. TiO₂/C-880 electrodes have high reversible specific capacities (404 mAh g^-1 at 0.1 A g^-1) and desirable long-term cyclic stability (100 mAh g^-1 at 2 A g^-1 throughout 2500 cycles). Moreover, large diffusion coefficients (D_Li⁺) ranging from 5.9 × 10^-11 to 1.2 × 10^-9 cm² s^-1 are obtained from galvanostatic intermittent titration (GITT) curves. The N-Ti-O/N-O-Ti and Ti-O-P bonds at the interfaces offer routes for fast Li⁺/electron transport, which account for the high performance of the TiO₂/C-880 electrodes.

Enhancing capacity and transport kinetics of C@TiO2core-shell composite anode by phase interface engineering

In nanocomposite electrodes, besides the synergistic effect that takes advantage of the merits of each component, phase interfaces between the components would contribute significantly to the overall electrochemical properties. However, the knowledge of such effects is far from being well developed up to now. The present work aims at a mechanistic understanding of the phase interface effect in C@TiO₂core-shell nanocomposite anode which is both scientifically and industrially important. Firstly, amorphous C, anatase TiO₂and C@anatse-TiO₂electrodes are compared. The C@anatase-TiO₂shows an obvious higher specific capacity (316.5 mAh g^-1at a current density of 37 mA g^-1after 100 cycles) and Li-ion diffusion coefficient (4.0 × 10^-14cm²s^-1) than the amorphous C (178 mAh g^-1and 2.9 × 10^-15cm²s^-1) and anatase TiO₂(120 mAh g^-1and 1.6 × 10^-15cm²s^-1) owing to the C/TiO₂phase interface effect. Then, C@anatase/rutile-TiO₂is obtained by a heat treatment of the C@anatase-TiO₂. Due to an anatase-to-rutile phase transformation and diffusion of C along the anatase/rutile phase interface, additional abundant C/TiO₂phase interfaces are created. This endows the C@anatase/rutile-TiO₂with further boosted specific capacity (409.4 mAh g^-1at 37 mA g^-1after 100 cycles) and Li-ion diffusion coefficient (3.2 × 10^-13cm²s^-1), and excellent rate capability (368.6 mAh g^-1at 444 mA g^-1). These greatly enhanced electrochemical properties explicitly reveal phase interface engineering as a feasible way to boost the electrochemical performance of nanocomposite anodes for Li-ion batteries.

Introducing Oxygen Vacancies in Li4Ti5O12 via Hydrogen Reduction for High-Power Lithium-Ion Batteries

Li4Ti5O12 (LTO), known as a zero-strain material, is widely studied as the anode material for lithium-ion batteries owing to its high safety and long cycling stability. However, its low electronic conductivity and Li diffusion coefficient significantly deteriorate its high-rate performance. In this work, we proposed a facile approach to introduce oxygen vacancies into the commercialized LTO via thermal treatment under Ar/H2 (5%). The oxygen vacancy-containing LTO demonstrates much better performance than the sample before H2 treatment, especially at high current rates. Density functional theory calculation results suggest that increasing oxygen vacancy concentration could enhance the electronic conductivity and lower the diffusion barrier of Li+, giving rise to a fast electrochemical kinetic process and thus improved high-rate performance.

Chemical Heterointerface Engineering on Hybrid Electrode Materials for Electrochemical Energy Storage

The chemical heterointerfaces in hybrid electrode materials play an important role in overcoming the intrinsic drawbacks of individual materials and thus expedite the in-depth development of electrochemical energy storage. Benefiting from the three enhancement effects of accelerating charge transport, increasing the number of storage sites, and reinforcing structural stability, the chemical heterointerfaces have attracted extensive interest and the electrochemical performances of hybrid electrode materials have been significantly optimized. In this review, recent advances regarding chemical heterointerface engineering in hybrid electrode materials are systematically summarized. Especially, the intrinsic behaviors of chemical heterointerfaces on hybrid electrode materials are refined based on built-in electric field, van der Waals interaction, lattice mismatch and connection, electron cloud bias and chemical bond, and their combination. The strategies for introducing chemical heterointerfaces are classified into in situ local transformation, in situ growth, cosynthesis, and other strategy. The recent progress about the chemical heterointerfaces engineering specially focusing on metal-ion batteries, supercapacitors, and Li-S batteries are introduced in detail. Furthermore, the classification and characterization of chemical heterointerfaces are briefly described. Finally, the emerging challenges and perspectives about future directions of chemical heterointerface engineering are proposed.

Sub-Thick Electrodes with Enhanced Transport Kinetics via In Situ Epitaxial Heterogeneous Interfaces for High Areal-Capacity Lithium Ion Batteries

The ever-growing portable electronics and electric vehicle draws the attention of scaling up of energy storage systems with high areal-capacity. The concept of thick electrode designs has been used to improve the active mass loading toward achieving high overall energy density. However, the poor rate capabilities of electrode material owing to increasing electrode thickness significantly affect the rapid transportation of ionic and electron diffusion kinetics. Herein, a new concept named "sub-thick electrodes" is successfully introduced to mitigate the Li-ion storage performance of electrodes. This is achieved by using commercial nickel foam (NF) to develop a monolithic 3D with rich in situ heterogeneous interfaces anode (Cu₃ P-Ni₂ P-NiO, denoted NF-CNNOP) to reinforce the adhesive force of the active materials on NF as well as contribute additional capacity to the electrode. The as-prepared NF-CNNOP electrode displays high reversible and rate areal capacities of 6.81 and 1.50 mAh cm^-2 at 0.40 and 6.0 mA cm^-2 , respectively. The enhanced Li-ion storage capability is attributed to the in situ interfacial engineering within the NiO, Ni₂ P, and Cu₃ P and the 3D consecutive electron conductive network. In addition, cyclic voltammetry, charge-discharge curves, and symmetric cell electrochemical impedance spectroscopy consistently reveal improved pseudocapacitance with enhanced transports kinetics in this sub-thick electrodes.

Aqueous Rechargeable Zn-ion Batteries: Strategies for Improving the Energy Storage Performance

The growing demand for the renewable energy storage technologies stimulated the quest for efficient energy storage devices. In recent years, the rechargeable aqueous zinc-based battery technologies are emerging as a compelling alternative to the lithium-based batteries owing to safety, eco-friendliness, and cost-effectiveness. Among the zinc-based energy devices, rechargeable zinc-ion batteries (ZIBs) are drawing considerable attention. However, they are plagued with several issues, including cathode dissolution, dendrite formation, etc.. Despite several efforts in the recent past, ZIBs are still in their infant stages and have yet to reach the stage of large-scale production. Finding stable Zn²⁺ intercalation cathode material with high operating voltage and long cycling stability as well as dendrite-free Zn anode is the main challenge in the development of efficient zinc-ion storage devices. This Review discusses the various strategies, in terms of the engineering of cathode, anode and electrolyte, adopted for improving the charge storage performance of ZIBs and highlights the recent ZIB technological innovations. A brief account on the history of zinc-based devices and various cathode materials tested for ZIB fabrication in the last five years are also included. The main focus of this Review is to provide a detailed account on the rational engineering of the electrodes, electrolytes, and separators for improving the charge storage performance with a future perspective to achieving high energy density and long cycling stability and large-scale production for practical application.

Interface-Driven Multifunctionality in Two-Dimensional TiO2 Nanosheet/Poly(Dimercaptothiadiazole-Triazine) Hybrid Resistive Random Access Memory Device

Interface-driven multifunctional facets are gearing up in the field of science and technology. Here, we present the interface-activated resistive switching (RS), negative differential resistance, diode behavior, and ultraviolet (UV) light sensing in nanosheet-based hybrid devices. A hybrid device i.e., titanium dioxide nanosheet (TiO₂-NS)/poly(dimercaptothiadiazole-triazine)[Poly(DMcT-CC)] is fabricated by spin coating Poly(DMcT-CC) polymer on hydrothermally as-grown TiO₂-NS. The pristine devices of both materials show either small or no magnitude of RS, but the hybrid device shows highly enhanced RS of nearly four orders due to the formation of a p-n junction at the NS/polymer interface. The resistive random access memory feature appears to be more prominent in the hybrid device i.e., high and low current states are found to be stable in repetitive cycles since the interface acts as a trapping center for the carriers. The UV sensing ability of the hybrid device has been demonstrated by a threefold increment in a current at 60 mV. The impedance spectroscopy has been employed to show that the multifunctional features are directly associated to the NS/polymer interface, which deduce that the manipulation of such interfaces can pave the way for developing the hybrid structures.

Constructing porous TiO2 crystals by an etching process for long-life lithium ion batteries

"Zero strain" materials, which have no volume change when charging and discharging, show ultra-long cycling stabilities when used as lithium-ion battery anodes, making them an area of extreme interest in this decade. For a typical anatase TiO₂ crystal, the volume change is 3-4% during Li insertion/extraction, which is not "zero strain". As the Ti/O packing in the TiO₂ lattice is too tight, there is insufficient void space for Li insertion, leading to volume expansion and structural collapse. Herein, pseudo-"zero-strain" TiO₂ is achieved via designing TiO₂ crystals with abundant inner mesopores, making Ti/O loose-packed via the acid-etching of K₂Ti₈O₁₇, providing sufficient space for Li intercalation. Instead of the traditional cut-off potential of 1 V used for Ti-/Nb-based anodes, we choose 0.01 V as the cut-off to make the best of the extra capacity contributed by the mesopores. As expected, plenty of mesopores could serve as "Li⁺-reservoirs" for fast lithium storage, demonstrating exceptional high-rate performance with an average capacity of 109.6 mA h g^-1 after 30 000 cycles at 60 C and 100 mA h g^-1 at 120 C. Such a strategy of combining a mesoporous structure and cut-off potential regulation may pave a solid pathway for constructing novel high-power anodes.

High areal capacitance of manganese oxide electrodes with cerium as rare earth modification

Manganese oxides have attracted wide attention as promising electrode materials for high-energy density supercapacitors. However, the electrochemical performance of the manganese oxide materials deteriorates considerably with the increase in mass loading due to their moderate electronic and ionic conductivities. This phenomenon leads to low areal capacitance, which limits the practical application of these materials. Herein, we perform a potentiostatic electrodeposition of manganese oxides with Ce as rare earth (RE) modification on a nickel (Ni) foam substrate to achieve high areal capacitance. Under optimum conditions, manganese oxide nanosheets are axially grown on Ni foam to form a hierarchically porous network nanostructure, which ensures facile ionic and electric transport. The Ce-modified manganese oxide with the Mn:Ce molar ratio of 1:0.1 yields an outstanding areal capacitance of 3.67 F cm^-2 at 2 mA cm^-2 and a good rate capability compared with the capacitance of 2.59 F cm^-2 at 2 mA cm^-2 of pure manganese oxide without the addition of Ce. This result verifies the importance of Ce modification to manganese oxides. Our results suggest the important role played by the RE element Ce in enhancing the electrochemical performance of high areal capacitance manganese oxide electrodes, which is essential to bringing them one step toward further practical applications.

Free-Standing Crystalline@Amorphous Core-Shell Nanoarrays for Efficient Energy Storage

Structures comprising high capacity active material are highly desirable in the development of advanced electrodes for energy storage devices. However, the structure degradation of such material still remains a challenge. The construction of amorphous and crystalline heterostructure appears to be a novel and effectual strategy to figure out the problem, owing to the distinct properties of the amorphous protective layer. Herein, crystalline-Co₃ O₄ @amorphous-TiO₂ core-shell nanoarrays directly grown on the carbon cloth substrate are rationally designed to construct the free-standing electrode. In the unique structure, the 3D porous nanoarrays provide increased availability of electrochemical active sites, and the array with a unique heterostructure of crystalline Co₃ O₄ core and amorphous TiO₂ shell exhibits intriguing synergistic properties. Besides, the amorphous TiO₂ protective layer shows elastic behavior to mitigate the volume effect of Co₃ O₄ . Benefiting from these structural advantages, the as-prepared free-standing electrode exhibits superior lithium storage properties, including high coulombic efficiency, outstanding cyclic stability, and rate capability. Pouch cells with high flexibility are also fabricated and show remarkable electrochemical performances, holding great potential for flexible electronic devices in the future.

Intercalation of Carbon Nanosheet into Layered TiO2 Grain for Highly Interfacial Lithium Storage

Interfacial energy storage contributes a new mechanism to the emergence of energy storage devices with not only a high-energy density of batteries but also a high-power density of capacitors. In this study, success was achieved in preparing a highly ordered two-dimensional (2D) carbon/TiO₂ (C/TiO₂) nanosheet composite using commercially available organic molecules with multifunctional groups and taking advantage of the wedge effects, oxidative polymerization, and carbonization. An experiment was conducted to validate the excellent performance of this 2D composite with respect to interfacial energy storage. The coin cell with 2D C/TiO₂ nanosheet composite demonstrates a specific capacity of as high as 510 mAh g^-1 and a high specific energy of 390.9 Wh kg^-1 at a specific power of 75.9 W kg^-1 with a current density of 0.1 A g^-1, and it also remains 39.0 Wh kg^-1 at a specific power of 8.2 kW kg^-1 with a high current density of 12.8 A g^-1. The excellent electrochemical performance can be attributed to the superior artificial interface capacitive Li⁺ storage capability, which would bridge the energy and power density gap between batteries and capacitors. Meanwhile, there are two varieties of carbon derivatives, 2D carbon nanosheet stacks and exfoliated carbon nanosheets, which can be obtained by wet-chemical etching and mechanical peeling. The experimental route is simple from commercially available raw materials, and it could be scalable at a low cost and large scale, which makes it suitable for application in various fields such as energy storage, nanocatalysis, sensors, and so on.

Synthesis of polyvalent ion reaction of MoS2/CoS2-RGO anode materials for high-performance sodium-ion batteries and sodium-ion capacitors

Metal sulfide is the most promising anode material for sodium storage devices due to its high theoretical capacity and low cost. However, the practical application of metal sulfide is largely hindered by huge capacity fading during the sodiation/desodiation process. Here mixed bimetallic sulfides grown on reduced graphene oxide (MoS₂/CoS₂-RGO) are prepared via a facile hydrothermal method. MoS₂/CoS₂-RGO displays a unique 2D structure which provides large specific surface area for pseudocapacitive charge storage, polyvalent ion reaction for ultrahigh capacity, and a heterostructure to high Na-ion diffusion rate. The optimized MoS₂/CoS₂-RGO shows a considerable reversible capacity of 593.6 mA h g^-1 at 100 mA g^-1 over 50 cycles and a high rate capability of 215.8 mA h g^-1 even at a high specific current of 5000 mA g^-1. A reaction kinetics and galvanostatic intermittent titration technique analysis indicates that MoS₂/CoS₂-RGO possesses fast pseudocapacitive charge storage and high Na-ion diffusion rate, benefiting the kinetics balance between anode and cathode. With this special structure, SICs containing the anode deliver a high specific energy of 152.98 W h kg^-1 at 562.5 W kg^-1. Similarly, the SIB exhibits a good capacities of 64 mA h g^-1 at the high rates of 5C over 100 cycles.

Two-Dimensional Layered Ultrathin Carbon/TiO2 Nanosheet Composites for Superior Pseudocapacitive Lithium Storage

Intercalation of carbon nanosheets into two-dimensional (2D) inorganic materials could enhance their properties in terms of mechanics and electrochemistry, but sandwiching these two kinds of materials in an alternating sequence is a great challenge in synthesis. Herein, we report a novel strategy to construct TiO₂ nanosheets into 2D pillar-layer architectures by employing benzidine molecular assembly as pillars. Then, 2D carbon/TiO₂ nanosheet composite with a periodic interlayer distance of 1.1 nm was obtained following a polymerization and carbonization process. This method not only alleviates the strain arising from the torsion of binding during carbonization but also hinders the structural collapse of TiO₂ due to the intercalation of the carbon layer by rational control of annealing conditions. The composite material possesses a large carbon/TiO₂ interface, providing abundant active sites for ultrafast pseudocapacitive charge storage, thus displaying a superior high-rate performance with a specific capacity of 67.8 mAh g^-1 at a current density of 12.8 A g^-1 based on the total electrode and excellent cyclability with 87.4% capacity retention after 3000 cycles.

High-Energy-Density Sodium-Ion Hybrid Capacitors Enabled by Interface-Engineered Hierarchical TiO2 Nanosheet Anodes

Sodium-ion hybrid capacitors are known for their high power densities and superior cycle life compared to Na-ion batteries. However, low energy densities (<100 Wh kg^-1) due to the lack of high-capacity (>150 mAh g^-1) anodes capable of fast charging are delaying their practical implementation. Herein, we report a high-performance Na-ion hybrid capacitor based on an interface-engineered hierarchical TiO₂ nanosheet anode consisting of bronze (∼15%) and anatase (∼85%) crystallites (∼10 nm). This pseudocapacitive dual-phase anode demonstrated exceptional specific capacity of 289 mAh g^-1 at 0.025 A g^-1 and excellent rate capability (110 mAh g^-1 at 1.0 A g^-1). The Na-ion hybrid capacitor integrating a dual-phase hierarchical TiO₂ nanosheet anode and an activated carbon cathode exhibited a high energy density of 200 Wh kg^-1 (based on the total mass of active materials in both electrodes) and power density of 6191 W kg^-1. These values are in the energy and power density range of Li-ion batteries (100-300 Wh kg^-1) and supercapacitors (5000-15 000 W kg^-1), respectively. Furthermore, exceptional capacity retention of 80% is observed after 5000 charge-discharge cycles. Outstanding electrochemical performance of the demonstrated Na-ion hybrid capacitor is credited to the enhanced pseudocapacitive Na-ion intercalation of the two-dimensional TiO₂ anode resulting from nanointerfaces between bronze and anatase crystallites. Mechanistic investigations evidenced Na-ion storage through intercalation pseudocapacitance with minimal structural changes. This approach of nanointerface-induced pseudocapacitance presents great opportunities toward developing advanced electrode materials for next-generation Na-ion hybrid capacitors.

Ti-Based Oxide Anode Materials for Advanced Electrochemical Energy Storage: Lithium/Sodium Ion Batteries and Hybrid Pseudocapacitors

Titanium-based oxides including TiO₂ and M-Ti-O compounds (M = Li, Nb, Na, etc.) family, exhibit advantageous structural dynamics (2D ion diffusion path, open and stable structure for ion accommodations) for practical applications in energy storage systems, such as lithium-ion batteries, sodium-ion batteries, and hybrid pseudocapacitors. Further, Ti-based oxides show high operating voltage relative to the deposition of alkali metal, ensuring full safety by avoiding the formation of lithium and sodium dendrites. On the other hand, high working potential prevents the decomposition of electrolyte, delivering excellent rate capability through the unique pseudocapacitive kinetics. Nevertheless, the intrinsic poor electrical conductivity and reaction dynamics limit further applications in energy storage devices. Recently, various work and in-depth understanding on the morphologies control, surface engineering, bulk-phase doping of Ti-based oxides, have been promoted to overcome these issues. Inspired by that, in this review, the authors summarize the fundamental issues, challenges and advances of Ti-based oxides in the applications of advanced electrochemical energy storage. Particularly, the authors focus on the progresses on the working mechanism and device applications from lithium-ion batteries to sodium-ion batteries, and then the hybrid pseudocapacitors. In addition, future perspectives for fundamental research and practical applications are discussed.

Composition- and size-modulated porous bismuth-tin biphase alloys as anodes for advanced magnesium ion batteries

Rechargeable magnesium batteries have huge potential for applications in large scale energy storage systems due to their low cost and abundant sources. Nevertheless, not much attention has been paid to the development of alternative anodes for magnesium ion batteries (MIBs). Herein, we demonstrate a scalable strategy to fabricate bismuth (Bi)-tin (Sn) biphase anodes with a porous (P) structure and controllable compositions/sizes, through the design of triphase precursors with immiscible elements (with a positive enthalpy of mixing between elements) and selective phase corrosion. Here, one phase was selected as the sacrificial component to form three-dimensional porous channels, which differs from the mechanism by which a porous structure is generated in a classical dealloying process. We systematically investigate how the composition and size of P-Bi-Sn anodes affect their Mg storage properties. As an anode for MIBs, the P-Bi3Sn2 electrode exhibits an excellent reversible capacity retention of over 93% for 200 cycles at 1000 mA g-1. Most importantly, the Mg storage mechanism of P-Bi-Sn anodes was unveiled by operando X-ray diffraction.

Self-Standing Metallic Mesh with MnO2 Multiscale Microstructures for High-Capacity Flexible Transparent Energy Storage

Flexible transparent electrochemical supercapacitors are critical components for the rapid development of fully flexible transparent electronics; however, typical flexible transparent supercapacitor electrodes store limited energy due to the requirements of transparency. Self-standing core-shell structure metal oxide mesh electrodes with metal oxide as active "shell" and metallic mesh as current collector "core" are efficient for simultaneously achieving high capacity, flexibility, and transparency. In this work, we perform a morphology-controlled electrodeposition of MnO₂ on a self-standing flexible transparent metallic Ni mesh electrode to achieve a high-capacity flexible transparent supercapacitor electrode. Under optimized conditions, the MnO₂ nanosheet-composed flowerlike multiscale microstructure was constructed. The open, loose, and porous MnO₂ multiscale microstructure "shell" and high electrical conductivity of self-standing metallic mesh "core" synergistically enable efficient ionic and electronic transport and meanwhile retain high structural stability. The metal oxide mesh electrode yields an outstanding areal capacitance of 1.15 F/cm² at an optical transmittance of 69.4% and excellent cycling stability. The symmetric solid-state supercapacitor device exhibits a high areal capacitance value (78.46 mF/cm²), superior cycling life, as well as high optical transmittance and mechanical flexibility, superior to the most reported flexible transparent supercapacitors. This work provides a comprehensive understanding on how to achieve high-capacity flexible transparent supercapacitor electrodes and solid-state devices.

Synthesis of Mesoporous TiO2-B Nanobelts with Highly Crystalized Walls toward Efficient H2 Evolution

Mesoporous TiO2 is attracting increasing interest due to properties suiting a broad range of photocatalytic applications. Here we report the facile synthesis of mesoporous crystalline TiO2-B nanobelts possessing a surface area as high as 80.9 m2 g-1 and uniformly-sized pores of 6-8 nm. Firstly, P25 powders are dissolved in NaOH solution under hydrothermal conditions, forming sodium titanate (Na2Ti3O7) intermediate precursor phase. Then, H2Ti3O7 is successfully obtained by ion exchange through acid washing from Na2Ti3O7 via an alkaline hydrothermal treatment. After calcination at 450 °C, the H2Ti3O7 is converted to a TiO2-B phase. At 600 °C, another anatase phase coexists with TiO2-B, which completely converts into anatase when annealed at 750 °C. Mesoporous TiO2-B nanobelts obtained after annealing at 450 °C are uniform with up to a few micrometers in length, 50-120 nm in width, and 5-15 nm in thickness. The resulting mesoporous TiO2-B nanobelts exhibit efficient H2 evolution capability, which is almost three times that of anatase TiO2 nanobelts.

Plasma-Introduced Oxygen Defects Confined in Li4Ti5O12 Nanosheets for Boosting Lithium-Ion Diffusion

Although Li₄Ti₅O₁₂ (LTO) is considered as a promising anode material for high-power Li-ion batteries with high safety, the sluggish Li-ion diffusion coefficient restricts its widespread application. In this work, oxygen vacancy was successfully incorporated into LTO by an eco-friendly and cost-effective plasma process. The deficient LTO delivers much higher capacities of 173.4 mAh g^-1 at 1C rate after 100 cycles and 140.5 mAh g^-1 at 5C after 1000 cycles than those of pristine LTO. Meanwhile, even at a high rate of 20C, it displays an ultrahigh capacity of 133.1 mAh g^-1 after 500 cycles with a Coulombic efficiency of 100%. Detailed analysis reveals that the lithium storage mechanisms in the oxygen-deficient LTO, especially at high rate, were dominated by the insertion behavior and dual-phase conversion due to the fast ion-diffusion ability, rather than the widely reported surface capacitance by other approaches. This work highlights that defect generation by plasma in nanomaterials is an effective way to promote ion mobility, especially at high rates, and thus can be extended to other electrode materials for advanced energy-storage applications.

Hollow Multishelled Heterostructured Anatase/TiO2 (B) with Superior Rate Capability and Cycling Performance

TiO₂ is a potential anode material for lithium-ion batteries due to its high rate capability and high safety. Here, a controllable synthesis for hollow nanostructured TiO₂ , with heterostructured shells of TiO₂ (B) and anatase phases, is presented for the first time, by using a sequential templating approach. The hollow nanostructures can be easily controlled to produce core-shell and double-shelled materials with different compositional ratios of anatase to TiO₂ (B) by tuning the synthetic conditions. When used as the anode materials for lithium-ion batteries, a specific discharge capacity of 215.4 mAh g^-1 for the double-shelled anatase/TiO₂ (B) hollow microspheres is achieved at a current rate of 1 C (335 mA g^-1 ) for the 100th cycle and shows high specific discharge capacities of 141.6 and 125.7 mAh g^-1 at the high rates of 10 and 20 C over 1000 cycles. These results are due to the unique stable hollow multishelled structure, which has a high specific surface area, as well as the interface between the heterostructured anatase/TiO₂ (B) phases contributing a substantial number of lithium-ion storage sites.

Tunable pseudocapacitive contribution by dimension control in nanocrystalline-constructed (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O solid solutions to achieve superior lithium-storage properties

Ultrafine crystalline materials have been extensively investigated as high-rate lithium-storage materials due to their shortened charge-transport length and high surface area. The pseudocapacitive effect plays a considerable role in electrochemical lithium storage when the electrochemically active materials approach nanoscale dimensions, but this has received limited attention. Herein, a series of (Mg_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2)O electrodes with different particle sizes were prepared and tested. The ultrafine (Mg_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2)O nanofilm (3–5 nm) anodes show a remarkable rate capability, delivering high specific charge and discharge capacities of 829, 698, 602, 498 and 408 mA h g⁻¹ at 100, 200, 500, 1000 and 2000 mA g⁻¹, respectively, and a dominant pseudocapacitive contribution as high as 90.2% toward lithium storage was revealed by electrochemical analysis at a high scanning rate of 1.0 mV s⁻¹. This work offers an approach to tune the lithium-storage properties of (Mg_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2)O by size control and gives insights into the enhancement of pseudocapacitance-assisted lithium-storage capacity.

A series of (Mg_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2)O electrodes with different particle sizes were prepared and tested, which presented excellent lithium-storage performance.

1D Sub-Nanotubes with Anatase/Bronze TiO2 Nanocrystal Wall for High-Rate and Long-Life Sodium-Ion Batteries

The development of 1D nanostructures with enhanced material properties has been an attractive endeavor for applications in energy and environmental fields, but it remains a major research challenge. Herein, this work demonstrates a simple, gel-derived method to synthesize uniform 1D elongated sub-nanotubes with an anatase/bronze TiO₂ nanocrystal wall (TiO₂ SNTs). The transformation mechanism of TiO₂ SNTs is studied by various ex situ characterization techniques. The resulting 1D nanostructures exhibit, synchronously, a high aspect ratio, open tubular interior, and anatase/bronze nanocrystal TiO₂ wall. This results in excellent properties of electron/ion transport and reaction kinetics. Consequently, as an anode material for sodium-ion batteries (SIBs), the TiO₂ SNTs display an ultrastable long-life cycling stability with a capacity of 107 mAh g^-1 at 16 C after 4000 cycles and a high-rate capacity of 94 mAh g^-1 at 32 C. This a high-rate and long-life performance is superior to any report on pure TiO₂ for SIBs. This work provides new fundamental information for the design and fabrication of inorganic structures for energy and environmental applications.

Polymer-Promoted Synthesis of Porous TiO2 Nanofibers Decorated with N-Doped Carbon by Mechanical Stirring for High-Performance Li-Ion Storage

Extensive efforts have been devoted to developing simple, low-cost, and high-production-yield methods to prepare hybrid materials with desired structural features for high-performance lithium storage. Here, a novel strategy is reported for fabricating the porous TiO₂ nanofibers decorated with N-doped carbon (TiO₂/C nanofibers) by a combination of mechanical stirring and the addition of a polymer in a beaker at ambient temperature, followed by calcination. The mechanical stirring process can provide homogeneous mixing of reactants in a solution, whereas the polymer acts not only as a structure-directing agent for fabricating one-dimensional nanofibers but also as the carbon and nitrogen source to generate N-doped carbon framework and porous structures. The TiO₂/C nanofibers have average diameters of 500 nm and lengths up to 65 μm and are further composed of intercrossed TiO₂ nanocrystals with sizes of 8 nm, with micropores centered at 1.5 nm and mesopores at 3-6 nm. The TiO₂/C electrodes demonstrated a high reversible capacity (368 mAh g^-1 at 0.25C after 200 cycles), good cycling performance (176 mAh g^-1 at 10C over 2000 cycles), and excellent rate capability (97 mAh g^-1 at 20C).

Porous Anatase-TiO2(B) Dual-Phase Nanorods Prepared from in Situ Pyrolysis of a Single Molecule Precursor Offer High Performance Lithium-Ion Storage

To overcome the problems faced by TiO₂ materials for lithium-ion batteries usage, such as easy nanoparticles agglomeration during cycling and poor cycling performance, in this study, TiO₂ nanorods with the controlled phase compositions are prepared via direct pyrolysis of single molecule precursors in combination with a simple washing process. By tuning the external cations in the single source precursors, three TiO₂ samples in a nanorod shape with the compositions of pure anatase, anatase-rutile dual phase, and anatase-TiO₂(B) dual phase are synthesized successfully. High-resolution transmission electron microscopy, X-ray powder diffraction, and Raman measurements confirm the phase structures and compositions of the three prepared samples. The electrochemical results manifest that all the three nanorod-shaped TiO₂ samples show the long-term cycling stability as negative materials for LIBs. Among them, the TiO₂ sample with the combination of the anatase and TiO₂-B phase shows the best performance, with the specific capacity of ∼184, 164, 140, 105, 80, and 60 mAh g^-1 at 0.1, 0.3, 0.5, 1.5, 3.0, and 5.0 A g^-1, respectively, and showing no capacity loss and low resistance after 1000 cycles at 1.5 A g^-1. By the analysis of the cyclic voltammetry results recorded from different scan rates, the lithium-ion storage mechanism is clarified, which is dominated by the semi-infinite linear diffusion (anatase phase) in combination with the partial surface pseudocapacitive contribution [TiO₂(B) phase]. As a result, this sample shows a great potential as a negative material for LIBs because of its electrochemical stability, high specific capacity, and superior rate capability. The proof-of-concept design of the anatase and TiO₂-B dual phase may provide a new strategy for the synthesis of high performance TiO₂-based anode material for LIBs.

Self-Reconstructed Formation of a One-Dimensional Hierarchical Porous Nanostructure Assembled by Ultrathin TiO2 Nanobelts for Fast and Stable Lithium Storage

Owing to their unique structural advantages, TiO₂ hierarchical nanostructures assembled by low-dimensional (LD) building blocks have been extensively used in the energy-storage/-conversion field. However, it is still a big challenge to produce such advanced structures by current synthetic techniques because of the harsh conditions needed to generate primary LD subunits. Herein, a novel one-dimensional (1D) TiO₂ hierarchical porous fibrous nanostructure constructed by TiO₂ nanobelts is synthesized by combining a room-temperature aqueous solution growth mechanism with the electrospinning technology. The nanobelt-constructed 1D hierarchical nanoarchitecture is evolves directly from the amorphous TiO₂/SiO₂ composite fibers in alkaline solutions at ambient conditions without any catalyst and other reactant. Benefiting from the unique structural features such as 1D nanoscale building blocks, large surface area, and numerous interconnected pores, as well as mixed phase anatase-TiO₂(B), the optimum 1D TiO₂ hierarchical porous nanostructure shows a remarkable high-rate performance when tested as an anode material for lithium-ion batteries (107 mA h g^-1 at ∼10 A g^-1) and can be used in a hybrid lithium-ion supercapacitor with very stable lithium-storage performance (a capacity retention of ∼80% after 3000 cycles at 2 A g^-1). The current work presents a scalable and cost-effective method for the synthesis of advanced TiO₂ hierarchical materials for high-power and stable energy-storage/-conversion devices.

High Mass Loading MnO2 with Hierarchical Nanostructures for Supercapacitors

Metal oxides have attracted renewed interest as promising electrode materials for high energy density supercapacitors. However, the electrochemical performance of metal oxide materials deteriorates significantly with the increase of mass loading due to their moderate electronic and ionic conductivities. This limits their practical energy. Herein, we perform a morphology and phase-controlled electrodeposition of MnO₂ with ultrahigh mass loading of 10 mg cm^-2 on a carbon cloth substrate to achieve high overall capacitance without sacrificing the electrochemical performance. Under optimum conditions, a hierarchical nanostructured architecture was constructed by interconnection of primary two-dimensional ε-MnO₂ nanosheets and secondary one-dimensional α-MnO₂ nanorod arrays. The specific hetero-nanostructures ensure facile ionic and electric transport in the entire electrode and maintain the structure stability during cycling. The hierarchically structured MnO₂ electrode with high mass loading yields an outstanding areal capacitance of 3.04 F cm^-2 (or a specific capacitance of 304 F g^-1) at 3 mA cm^-2 and an excellent rate capability comparable to those of low mass loading MnO₂ electrodes. Finally, the aqueous and all-solid asymmetric supercapacitors (ASCs) assembled with our MnO₂ cathode exhibit extremely high volumetric energy densities (8.3 mWh cm^-3 at the power density of 0.28 W cm^-3 for aqueous ASC and 8.0 mWh cm^-3 at 0.65 W cm^-3 for all-solid ASC), superior to most state-of-the-art supercapacitors.

Hierarchical Porous Nanosheets Constructed by Graphene-Coated, Interconnected TiO2 Nanoparticles for Ultrafast Sodium Storage

Sodium-ion batteries (SIBs) are considered promising next-generation energy storage devices. However, a lack of appropriate high-performance anode materials has prevented further improvements. Here, a hierarchical porous hybrid nanosheet composed of interconnected uniform TiO₂ nanoparticles and nitrogen-doped graphene layer networks (TiO₂ @NFG HPHNSs) that are synthesized using dual-functional C₃ N₄ nanosheets as both the self-sacrificing template and hybrid carbon source is reported. These HPHNSs deliver high reversible capacities of 146 mA h g^-1 at 5 C for 8000 cycles, 129 mA h g^-1 at 10 C for 20 000 cycles, and 116 mA h g^-1 at 20 C for 10 000 cycles, as well as an ultrahigh rate capability up to 60 C with a capacity of 101 mA h g^-1 . These results demonstrate the longest cyclabilities and best rate capability ever reported for TiO₂ -based anode materials for SIBs. The unprecedented sodium storage performance of the TiO₂ @NFG HPHNSs is due to their unique composition and hierarchical porous 2D structure.

Electrostatic Self-Assembly Enabling Integrated Bulk and Interfacial Sodium Storage in 3D Titania-Graphene Hybrid

Room-temperature sodium-ion batteries have attracted increased attention for energy storage due to the natural abundance of sodium. However, it remains a huge challenge to develop versatile electrode materials with favorable properties, which requires smart structure design and good mechanistic understanding. Herein, we reported a general and scalable approach to synthesize three-dimensional (3D) titania-graphene hybrid via electrostatic-interaction-induced self-assembly. Synchrotron X-ray probe, transmission electron microscopy, and computational modeling revealed that the strong interaction between titania and graphene through comparably strong van der Waals forces not only facilitates bulk Na⁺ intercalation but also enhances the interfacial sodium storage. As a result, the titania-graphene hybrid exhibits exceptional long-term cycle stability up to 5000 cycles, and ultrahigh rate capability up to 20 C for sodium storage. Furthermore, density function theory calculation indicated that the interfacial Li⁺, K⁺, Mg^2+, and Al³⁺ storage can be enhanced as well. The proposed general strategy opens up new avenues to create versatile materials for advanced battery systems.