Pseudocapacitive Behaviors of Li2FeTiO4/C Hybrid Porous Nanotubes for Novel Lithium-Ion Battery Anodes with Superior Performances

Promoted kinetics and capacity on the Li2CuTi3O8/C anode by constructing a one dimensional hybrid structure for superior performance lithium ion batteries

Notably, spinel Li2CuTi3O8 with higher theoretical capacity inherits the characteristics of Li4Ti5O12, which is a promising anode material for lithium ion batteries with high energy density. However, the reversible migration of Cu2+ in Li2CuTi3O8 during the discharge process limits the diffusion of Li+, resulting in poor electrochemical performance. Space confinement is a desirable successful strategy to reduce the size of electroactive materials in return for getting improved kinetics and capacity for secondary ion batteries. Here, we develop a strategy by controlling the precursor of Li2CuTi3O8 in the walls of sulfonated polymer nanotubes, and the highly crosslinked copolymer network in the process of pyrolysis caused strong space confinement for the nanoparticles, which effectively prevented the agglomeration of Li2CuTi3O8 during the calcination process. The hybrid porous nanotubes consisting of Li2CuTi3O8 nanoparticles (5-50 nm) embedded in carbon nanotubes exhibit superior performance (402.8 mA h g-1 at 0.2 A g-1, 101 mA h g-1 at 10 A g-1 after 1000 cycles). This work provides a rapid and durable Li2CuTi3O8 electrochemistry, holding great promise in developing a practically viable Li2CuTi3O8 anode and enlightening material engineering in related energy storage and conversion areas.

Novel Fe4-based metal-organic cluster-derived iron oxides/S,N dual-doped carbon hybrids for high-performance lithium storage

Metal-organic frameworks (MOFs) have been extensively used in the fabrication of new advanced electrode materials for lithium ion batteries (LIBs). However, low-productivity and high-cost are some of the main challenges of MOF-derived electrodes. Herein, we report a simple solvothermal procedure to fabricate novel Fe4-based metal-organic clusters (Fe-MOCs) with their subsequent conversion to an S,N dual-doped carbon framework incorporating iron oxides under a N2 atmosphere (namely Fe2O3@Fe3O4-SNC). The as-prepared Fe2O3@Fe3O4-SNC composite, owing to the strong interaction between the dual-doped carbon and iron oxides, shows excellent lithium storage performance as an anode with high pseudocapacitance. Furthermore, DFT computational analyses confirm that the hybrid shows excellent adsorption ability with a low energy barrier due to strong electronic interactions between the iron oxides and S,N-doped carbon matrix. In addition, Fe2O3@Fe3O4-SNC-based LIB shows high energy and power densities at the full-cell level, confirming this synthesis strategy to be a promising approach towards MOC-derived electrode materials for their application in LIBs and beyond-lithium batteries.

Rational design of FeTiO3/C hybrid nanotubes: promising lithium ion anode with enhanced capacity and cycling performance

Ilmenite FeTiO3 has the advantage of high theoretical capacity and abundant sources as an anode material for lithium-ion batteries (LIBs). However, it suffers inferior rate capability caused by the aggregation of particles. To solve this problem, FeTiO3 nanoparticles embedded in porous CNTs were developed by the sol-gel route and subsequent calcination. The unique hybrids have a uniform distribution of FeTiO3 nanoparticles (5-20 nm) in the carbon matrix. Electrochemical tests prove that the porous FeTiO3/C hybrid nanotubes deliver a high capacity of 612.5 mA h g-1 at 0.2 A g-1 after 300 cycles. Moreover, they present remarkable rate capability and exceptional cycling stability, possessing 163.8 mA h g-1 at 5 A g-1 for 1000 cycles. The enhanced electrochemical performance of the FeTiO3/C hybrid is derived from the shortened Li+ transport length, good structure stability and conductive carbon matrix, which simultaneously solves the major problems of pulverization and agglomeration of FeTiO3 nanoparticles during cycling.

Construction of the NaTi2(PO4)3/C electrode with a one-dimensional porous hybrid structure as an advanced anode for sodium-ion batteries

The inferior electronic conductivity of NASICON materials leads to poor cyclability and rate capability, which severely inhibits their extensive development. Therefore, we have developed a one-dimensional (1D) hybrid electrode material that combines small NaTi2(PO4)3 nanoparticles (5-50 nm) with a porous carbon matrix using a controllable sol-gel strategy. This unique design enables the electrode to possess good structural stability, superior charge transfer kinetics, and low polarization. The intimate combination between the nanoparticles and the porous carbon matrix can effectively facilitate Na+/e- transfer and accommodate volume variation during cycling. The construction of the new structure presented in this work will extend the applications of the NaTi2(PO4)3 system. Furthermore, the formed hybrid structure has potential to be a universal model for various electrode materials.

Li(Na)2FeSiO4/C hybrid nanotubes: promising anode materials for lithium/sodium ion batteries

Porous Li(Na)₂FeSiO₄/C hybrid nanotubes were successfully synthesized by a modified sol–gel strategy and a subsequent calcination process. These nanohybrids exhibited excellent electrochemical performances as anodes for lithium/sodium ion batteries.

Enhanced gas sensing performance of perovskite YFe1−xMnxO3 by doping manganese ions

The gas sensitive performance of perovskite YFe_1−xMn_xO₃ can be tailored effectively by simple manganese ion doping.

Cable-like heterogeneous porous carbon fibers with ultrahigh-rate capability and long cycle life for fast charging lithium-ion storage devices

In this paper, we propose a space-confined foaming approach to fabricate cable-like heterogeneous porous carbon fibers (Si-CPCFs) containing an inner graphitized carbon "conductor" and an outer Si-doping amorphous carbon "shield". Benefiting from the fast Li⁺ intercalation and high conductivity of the "inner conductor", and the rich pseudocapacitance of the "outer shield", the Si-CPCFs exhibit an ultrahigh-rate capability and cycling performance, leading to a high capacity of 132 mA h g^-1 even at an ultra-high current density of 100 A g^-1 after 10 000 cycles. The assembled lithium ion hybrid supercapacitors (LIHCs) also deliver a superior energy density of 50 W h kg^-1 at an ultra-high power density of 113 kW kg^-1, really achieving both a high energy density and power density of LIHCs. The success of the cable-like heterogeneous porous carbon architecture proposes a new direction to circumvent the discrepancy in kinetics and capacity mismatch, and also attracts more attention to heterogeneous nanostructures with multiple functions.

H0.92K0.08TiNbO5 Nanowires Enabling High-Performance Lithium-Ion Uptake

HTiNbO₅ has been widely investigated in many fields because of its distinctive properties such as good redox activity, high photocatalytic activity, and environmental benignancy. Here, this work reports the synthesis of one-dimensional H_0.92K_0.08TiNbO₅ nanowires via simple electrospinning followed by an ion-exchange reaction. The H_0.92K_0.08TiNbO₅ nanowires consist of many small "lumps" with a uniform diameter distribution of around 150 nm. Used as an anode for lithium-ion batteries, H_0.92K_0.08TiNbO₅ nanowires exhibit high capacity, fast electrochemical kinetics, and high performance of lithium-ion uptake. A capacity of 144.1 mA h g^-1 can be carried by H_0.92K_0.08TiNbO₅ nanowires at 0.5 C in the initial charge, and even after 150 cycles, the reversible capacity can remain at 123.7 mA h g^-1 with an excellent capacity retention of 85.84%. For H_0.92K_0.08TiNbO₅ nanowires, the diffusion coefficient of lithium ions is 1.97 × 10^-11 cm² s^-1, which promotes the lithium-ion uptake effectively. The outstanding electrochemical performance is ascribed to its morphology and the formation of a stable phase during cycling. In addition, the in situ X-ray diffraction and ex situ transmission electron microscopy techniques are applied to reveal its lithium storage mechanism, which proves the structure stability and electrochemical reversibility, thus achieving high-performance lithium-ion uptake. All these advantages demonstrate that H_0.92K_0.08TiNbO₅ nanowires can be a possible alternative anode material for rechargeable batteries.

Facile fabrication of a jarosite ultrathin KFe3(SO4)2(OH)6@rGO nanosheet hybrid composite with pseudocapacitive contribution as a robust anode for lithium-ion batteries

Earth-abundant and acid-resistant KFe₃(SO₄)₂(OH)₆@rGO nanosheets deliver stable lithium storage properties, owing to the induced pseudocapacitive contribution.