Air-Stable and High-Voltage Layered P3-Type Cathode for Sodium-Ion Full Battery

Interfacial Spinel Local Interlocking Strategy Toward Structural Integrity in P3 Oxide Cathodes

P3-layered transition oxide cathodes have garnered considerable attention owing to their high initial capacity, rapid Na+ kinetics, and less energy consumption during the synthesis process. Despite these merits, their practical application is hindered by the substantial capacity degradation resulting from unfavorable structural transformations, Mn dissolution and migration. In this study, we systematically investigated the failure mechanisms of P3 cathodes, encompassing Mn dissolution, migration, and the irreversible P3-O3' phase transition, culminating in severe structural collapse. To address these challenges, we proposed an interfacial spinel local interlocking strategy utilizing P3/spinel intergrowth oxide as a proof-of-concept material. As a result, P3/spinel intergrowth oxide cathodes demonstrated enhanced cycling performance. The effectiveness of suppressing Mn migration and maintaining local structure of interfacial spinel local interlocking strategy was validated through depth-etching X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and in situ synchrotron-based X-ray diffraction. This interfacial spinel local interlocking engineering strategy presents a promising avenue for the development of advanced cathode materials for sodium-ion batteries.

Routes to high-performance layered oxide cathodes for sodium-ion batteries

Sodium-ion batteries (SIBs) are experiencing a large-scale renaissance to supplement or replace expensive lithium-ion batteries (LIBs) and low energy density lead-acid batteries in electrical energy storage systems and other applications. In this case, layered oxide materials have become one of the most popular cathode candidates for SIBs because of their low cost and comparatively facile synthesis method. However, the intrinsic shortcomings of layered oxide cathodes, which severely limit their commercialization process, urgently need to be addressed. In this review, inherent challenges associated with layered oxide cathodes for SIBs, such as their irreversible multiphase transition, poor air stability, and low energy density, are systematically summarized and discussed, together with strategies to overcome these dilemmas through bulk phase modulation, surface/interface modification, functional structure manipulation, and cationic and anionic redox optimization. Emphasis is placed on investigating variations in the chemical composition and structural configuration of layered oxide cathodes and how they affect the electrochemical behavior of the cathodes to illustrate how these issues can be addressed. The summary of failure mechanisms and corresponding modification strategies of layered oxide cathodes presented herein provides a valuable reference for scientific and practical issues related to the development of SIBs.

Developing an abnormal high-Na-content P2-type layered oxide cathode with near-zero-strain for high-performance sodium-ion batteries

Layered transition metal oxides (NaxTMO2) possess attractive features such as large specific capacity, high ionic conductivity, and a scalable synthesis process, making them a promising cathode candidate for sodium-ion batteries (SIBs). However, NaxTMO2 suffer from multiple phase transitions and Na+/vacancy ordering upon Na+ insertion/extraction, which is detrimental to their electrochemical performance. Herein, we developed a novel cathode material that exhibits an abnormal P2-type structure at a stoichiometric content of Na up to 1. The cathode material delivers a reversible capacity of 108 mA h g-1 at 0.2C and 97 mA h g-1 at 2C, retaining a capacity retention of 76.15% after 200 cycles within 2.0-4.3 V. In situ diffraction studies demonstrated that this material exhibits an absolute solid-solution reaction with a low volume change of 0.8% during cycling. This near-zero-strain characteristic enables a highly stabilized crystal structure for Na+ storage, contributing to a significant improvement in battery performance. Overall, this work presents a simple yet effective approach to realizing high Na content in P2-type layered oxides, offering new opportunities for high-performance SIB cathode materials.

Multifunctional Effect of Fe Substitution in Na Layered Cathode Materials for Enhanced Storage Stability

Developing stable cathode materials that are resistant to storage degradation is essential for practical development and industrial processing of Na-ion batteries as many sodium layered oxide materials are susceptible to hygroscopicity and instability upon exposure to ambient air. Among the various layered compounds, Fe-substituted O3-type Na(Ni1/2Mn1/2)1-xFexO2 materials have emerged as a promising option for high-performance and low-cost cathodes. While previous reports have noted the decent air-storage stability of these materials, the role and origin of Fe substitution in improving storage stability remain unclear. In this study, we investigate the air-resistant effect of Fe substitution in O3-Na(Ni1/2Mn1/2)1-xFexO2 cathode materials by performing systematic surface and structural characterizations. We find that the improved storage stability can be attributed to the multifunctional effect of Fe substitution, which forms a surface protective layer containing an Fe-incorporated spinel phase and decreases the thermodynamical driving force for bulk chemical sodium extraction. With these mechanisms, Fe-containing cathodes can suppress the cascades of cathode degradation processes and better retain the electrochemical performance after air storage.

Rational design of intergrowth P2/O3 biphasic layered structure with reversible anionic redox chemistry and structural evolution for Na-ions batteries

Layered oxides have attracted unprecedented attention for their outstanding performance in sodium-ion battery cathodes. Among them, the two typical candidates P2 and O3 type materials generally demonstrate large diversities in specific capacity and cycling endurance with their advantages. Thus, composite materials that contain both P2 and O3 have been widely designed and constructed. Nevertheless, the anionic/cationic ions' behavior and structural evolution in such complex structures remain unclear. In this study, a deep analysis of an advanced Na_0.732Ni_0.273Mg_0.096Mn_0.63O₂ material that contains 78.39 wt% P2 phase and 21.61 wt% O3 phase is performed based on two typical cathodes P2 Na_0.67Ni_0.33Mn_0.67O2 and O3 NaNi_0.5Mn_0.5O₂ that have the same elemental constitution but different crystal structures. Structural analysis and density functional theory (DFT) calculations suggest that the composite is preferred to form a symbiotic structure at the atomic level, and the complex lattice texture of the biphase structure can block unfavorable ion and oxygen migration in the electrode process. Consequently, the biphase structure has significantly improved the electrochemical performance and kept preferable anionic oxygen redox reversibility. Furthermore, the hetero-epitaxy-like structure of the intergrowth of P2 and O3 structures share multi-phase boundaries, where the inconsistency in electrochemical behavior between P2 and O3 phases leads to an interlocking effect to prevent severe structural collapse and relieves the lattice strain from Na⁺ de/intercalation. Hence, the symbiotic P2/O3 composite materials exhibited a preferable capacity and cyclability (∼130 mAh g^-1 at 0.1 C, 73.1% capacity retention after 200 cycles at 1 C), as well as reversible structural evolution. These findings confirmed the advantages of using the bi/multi-phase cathode for high-energy Na-ion batteries.

Fluorine Substitution Promotes Air-Stability of P'2-Type Layered Cathodes for Sodium-Ion Batteries

As one of the most promising cathode materials in sodium-ion batteries, manganese-based layered oxides have aroused wide attention due to their high specific capacity and plentiful reserves. However, they are plagued by poor air stability rooting in water/Na⁺ exchange and adverse structural reconstruction, hindering their practical applications. Herein, it is demonstrated that utilizing fluorine to substitute oxygen atoms can narrow the interlayer spacing of novel P'2-Na_0.67 MnO_1.97 F_0.03 (NMOF) cathode material, which resists the attack of water molecules, significantly prolonging exposure time in air. Density functional theory (DFT) calculation results indicate that fluorine substitution alleviates the insertion of water molecules and spontaneous extraction of Na⁺ effectively. Benefiting from the structural modulation, NMOF can deliver a high specific capacity of 227.1 mAh g^-1 at 20 mA g^-1 and a promising capacity retention of 84.0% after 100 cycles at 200 mA g^-1 . This facile and available strategy provides a feasible way to strengthen the air-stability and expands the scope of practical applications of layered oxide cathodes.

Correlation between the Cation Disorders of Fe3+ and Li+ in P3-Type Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2 for Sodium Ion Batteries

Various Fe-based layered oxide materials have received attention as promising cathode materials for sodium ion batteries because of their low cost and high specific capacity. Only a few P3-type Fe-based oxide materials, however, have been examined as cathodes because the synthesis of highly crystalline P3-type Fe-based oxides is not facile. For this reason, the structural merits of the P3 structure are not yet fully understood. Herein, highly crystalline P3-type Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2 heated at 900 °C is introduced to improve the electrochemical performance of Fe-based layered oxides. The structures, reaction mechanisms, and electrochemical performances of P3 Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2, P2 Na0.57[Li0.1(Fe0.5Mn0.5)0.9]O2, and P2 Na0.67[Fe0.5Mn0.5]O2 are compared to demonstrate the roles of Li+ doping in the improved electrochemical performance of P3 Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2, such as stable capacity retention over 100 cycles. P3 Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2 significantly suppresses the migration of Fe3+ ions to tetrahedral sites in the Na layer during cycling because the cation disorder of Li+ is more favorable than that of Fe3+. As a result, P3 Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2 shows better cycle performance than P2 Na0.67[Fe0.5Mn0.5]O2. P3 Na0.67[Li0.1(Fe0.5Mn0.5)0.9]O2 also exhibits an improved rate performance compared to P2 Na0.67[Fe0.5Mn0.5]O2. This finding provides fundamental insights to improve the electrochemical performance of layered oxide cathode materials for sodium ion batteries.

Ion Substitution Strategy of Manganese-Based Layered Oxide Cathodes for Advanced and Low-Cost Sodium Ion Batteries

Sodium ion batteries (SIBs) have recently been promising in the large-scale electric energy storage system, due to the low cost, abundant sodium resources. Mn-based layered oxide cathode materials have been widely investigated, because of the high theoretical specific capacity, low cost, and abundant reserves. However, their development is limited by the problems of Jahn-Teller distortion, Na⁺ /vacancy ordering, complex phase transitions, and irreversible anionic redox during cycling. Ion substitution strategy is one simple and effective way to regulate the crystal structure and boost sodium-storage performances of Mn-based cathode materials. In this review, we summarize the progress and mechanism of ion-substituted Mn-based oxides, establish a composition-crystal structure-electrochemical performance relationship, and also offer perspectives for guiding the design of high-performance Mn-based oxides for SIBs.

Organic Small Molecules with Electrochemical-Active Phenolic Enolate Groups for Ready-to-Charge Organic Sodium-Ion Batteries

Organic materials have attracted much attention in sodium ion batteries (SIBs) because of their advantages such as being environmentally benign and having high designability. Capacities and cycle life of organic materials are the most important parameters in most research which has been paid much effort to obtain an impressive electrochemical performance on the material level, and the sodium-detachable ability of these materials to directly match with the sodium-free anode is neglected. In this work, one organic sodium salt (C₆ H₂ Na₂ O₆ ) exhibits the unique ability (charging first in half cell) unlike other reported organic cathode materials (normally discharging first) for SIBs. The redox mechanism and structure change are investigated by in situ and ex situ tests to give a better understanding for C₆ H₂ Na₂ O₆ . Satisfying electrochemical performance (74% capacity retention after 600 cycles at 0.05 A g^-1 and 63% capacity retention at 5 A g^-1 when compared with capacity at 0.05 A g^-1 ) is achieved by the C₆ H₂ Na₂ O₆ electrode. In addition, matched with hard carbon, full cells are assembled successfully like other transition metal containing cathode materials because C₆ H₂ Na₂ O₆ electrode can deliver its sodium ions to a sodium-free anode directly without any presodiation.

Recent Advances in Layered Metal-Oxide Cathodes for Application in Potassium-Ion Batteries

To meet future energy demands, currently, dominant lithium-ion batteries (LIBs) must be supported by abundant and cost-effective alternative battery materials. Potassium-ion batteries (KIBs) are promising alternatives to LIBs because KIB materials are abundant and because KIBs exhibit intercalation chemistry like LIBs and comparable energy densities. In pursuit of superior batteries, designing and developing highly efficient electrode materials are indispensable for meeting the requirements of large-scale energy storage applications. Despite using graphite anodes in KIBs instead of in sodium-ion batteries (NIBs), developing suitable KIB cathodes is extremely challenging and has attracted considerable research attention. Among the various cathode materials, layered metal oxides have attracted considerable interest owing to their tunable stoichiometry, high specific capacity, and structural stability. Therefore, the recent progress in layered metal-oxide cathodes is comprehensively reviewed for application to KIBs and the fundamental material design, classification, phase transitions, preparation techniques, and corresponding electrochemical performance of KIBs are presented. Furthermore, the challenges and opportunities associated with developing layered oxide cathode materials are presented for practical application to KIBs.

Heteroatom-Substituted P2-Na2/3Ni1/4Mg1/12Mn2/3O2 Cathode with {010} Exposing Facets Boost Anionic Activity and High-Rate Performance for Na-Ion Batteries

As an attractive cathode candidate for sodium-ion batteries, P2-type Na_2/3Ni_1/3Mn_2/3O₂ is famous for its high stability in humid air, attractive capacity, and high operating voltage. However, the low Na⁺ transport kinetics, oxygen-redox reactions, and irreversible structural evolution at high-voltage areas hinder its practical application. Herein, a comprehensive study of a microbar P2-type Ni_2/3Ni_1/4Mg_1/12Mn_2/3O₂ material with {010} facets is presented, which exhibits high reversibility of structural evolution and anionic redox activity, leading to outstanding rate capability and cyclability. The notable rate performance (53 mA h g^-1 at 20 C, 2.0-4.3 V) contributed to the high exposure of {010} facets via controlling the growth orientation of the precursor, which is certified by density functional theory calculation and lattice structural analysis. Mg substitution strengthens the reversibility of anionic oxygen redox and structural evolution in high-voltage areas that was confirmed by the in situ X-ray diffraction and ex situ X-ray photoelectron spectroscopy tests, leading to outstanding cyclic reversibility (68.9% after 1000 cycles at 5 C) and slowing down the voltage fading. This work provides new insights into constructing electrochemically active planes combined with heteroatom substitution to improve the Na⁺ transport kinetics and structural stability of layered oxide cathodes for sodium storage.

Challenges of layer-structured cathodes for sodium-ion batteries

As the most promising alternative to lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) still face many issues that hinder their large-scale commercialization. Layered transition metal oxide cathodes have attracted widespread attention owing to their large specific capacity, high ionic conductivity, and feasible preparation conditions. However, their electrochemical properties are usually limited by the irreversible phase transition and harsh storage conditions caused by humidity sensitivity. Recently, tremendous efforts have been devoted to solving these issues toward advanced high-performance layered oxide cathodes. Herein, we summarize these remaining challenges of layered oxide cathodes and the corresponding modification strategies such as the variations in chemical compositions, the architecture of (nano)micro-structures, surface engineering, and the regulation of phase compositions. We hope that the understanding presented in this review can provide useful guidance to developing high-performance layer-structured cathode materials for advanced SIBs.

Manipulating Stable Layered P2-Type Cathode via a Co-Substitution Strategy for High Performance Sodium Ion Batteries

Mn-based layered transition metal oxides (TMOs) are promising cathodes for sodium ion batteries (SIBs) due to their eco-friendly character and abundant natural reserves. However, the complex phase changes and structural instability of the Mn-based layered TMO cathodes during electrochemical process are major hindrances to meet the commercial application. Cation substitution is an effective way to stabilize the structure and accelerate the Na⁺ kinetics of cathode materials. Herein, an intriguing layered P2-type Mn-based Na_0.7 Li_0.06 Zn_0.06 Ni_0.21 Mn_0.67 O₂ material is reported by substitution of Li and Zn for partial Ni. The occupation of inert elements on Ni sites could well maintain the crystal structure, giving rise to a prominent cycle life and improved electrochemical kinetics. The as-prepared electrode presents an initial discharge capacity of 131.8 mA h g^-1 at 20 mA g^-1 and preserves 91.9% capacity after 100 cycles, accompanied with enexcellent rate performance (108 mA h g^-1 at 500 mA g^-1 ). Furthermore, the single-phase reaction mechanism during the sodiation/desodiation process is verified by in situ X-ray diffraction. Additionally, theory computations prove the decreased migration energy barriers and enhanced Na⁺ kinetics ulteriorly. This dual-doping strategy inspires an effective way to produce high performance cathode materials for SIBs.

Validating the Structural (In)stability of P3- and P2-Na0.67Mg0.1Mn0.9O2-Layered Cathodes for Sodium-Ion Batteries: A Time-Decisive Approach

In this study, magnesium-ion-substituted, sodium-deficient, P3- and P2-layered manganese oxide cathodes (Na_0.67Mg_0.1Mn_0.9O₂) were synthesized through a facile polyol-assisted combustion technique for applications in sodium-ion batteries. The electrochemical reaction pathways, structural integrity, and long cycling ability at low current rates of the P3- and P2-phases of the Na_0.67Mg_0.1Mn_0.9O₂ cathodes were investigated using time-consuming techniques, such as galvanostatic titration and series cyclic voltammetry. The results obtained from these techniques were supported by those obtained from operando X-ray diffraction (XRD) analysis. Particularly, the P2-phase provided excellent structural stability owing to its intrinsic crystal structure, thereby exhibiting a reversible capacity retention of 82.6% after 262 cycles at a low rate of 0.1 C; in contrast, the P3-phase exhibited a capacity retention of 38.7% after 241 cycles at a similar current rate. The air stability of these as-prepared powders, which were stored under ambient conditions, was progressively analyzed over a period of 6 months through XRD without conducting any special experiments. The results suggest that in the P3-phase, the formation of NaHCO₃ and hydrated phase impurities, resulting from Na⁺/H⁺ exchange and hydration reactions, respectively, was likely to occur more quickly, that is, within a few days, compared to that in the P2-phase.

Cation-Disordered O3-Na0.8Ni0.6Sb0.4O2 Cathode for High-Voltage Sodium-Ion Batteries

O3-type sodium-layered oxides (such as antimony-based O3 structures) have been suggested as one of the most fascinating cathode materials for sodium-ion batteries (SIBs). Honeycomb-ordered antimony-based O3 structures, however, unsatisfactorily exhibit complex phase transitions and sluggish Na⁺ kinetics during cycling. Herein, we prepared a completely cationic-disordered O3-type Na_0.8Ni_0.6Sb_0.4O₂ compound by composition regulation for SIBs. Surprisingly, the measured redox potentials for typical O3-P3 phase transition are located at 3.4 V. Operando X-ray diffraction confirms a reversible phase transition process from the O3 to P3 structure accompanied with a very small volume change (1.0%) upon sodium extraction and insertion. The low activation barrier energy of 400 meV and the fast Na⁺ migration of 10^-11 cm²·s^-1 are further obtained by first-principles calculations and galvanostatic intermittent titration technique, respectively. As a result, the O3-Na_0.8Ni_0.6Sb_0.4O₂ cathode displays a reversible capacity of 106 mA h g^-1 at 0.1C (12 mA g^-1), smooth charge-discharge curves, and a high average working voltage of 3.5 V during battery cycling. The results highlight the importance of searching for a new O3-type structure with cation-disordering and high working voltage for realizing high energy SIBs.

Role of Lithium Doping in P2-Na0.67Ni0.33Mn0.67O2 for Sodium-Ion Batteries

P2-structured Na_0.67Ni_0.33Mn_0.67O₂ (PNNMO) is a promising Na-ion battery cathode material, but its rapid capacity decay during cycling remains a hurdle. Li doping in layered transition-metal oxide (TMO) cathode materials is known to enhance their electrochemical properties. Nevertheless, the influence of Li at different locations in the structure has not been investigated. Here, the crystallographic role and electrochemical impact of lithium on different sites in PNNMO is investigated in Li _x Na_0.67-y Ni_0.33Mn_0.67O_2+δ (0.00 ≤ x ≤ 0.2, y = 0, 0.1). Lithium occupancy on prismatic Na sites is promoted in Na-deficient (Na < 0.67) PNNMO, evidenced by ex situ and operando synchrotron X-ray diffraction, X-ray absorption spectroscopy, and ⁷Li solid-state nuclear magnetic resonance. Partial substitution of Na with Li leads to enhanced stability and slightly increased specific capacity compared to PNNMO. In contrast, when lithium is located primarily on octahedral TM sites, capacity is increased but at the cost of stability.

P3/O3 Integrated Layered Oxide as High-Power and Long-Life Cathode toward Na-Ion Batteries

Low-cost and stable sodium-layered oxides (such as P2- and O3-phases) are suggested as highly promising cathode materials for Na-ion batteries (NIBs). Biphasic hybridization, mainly involving P2/O3 and P2/P3 biphases, is typically used to boost their electrochemical performances. Herein, a P3/O3 intergrown layered oxide (Na_2/3 Ni_1/3 Mn_1/3 Ti_1/3 O₂ ) as high-rate and long-life cathode for NIBs via tuning the amounts of Ti substitution in Na_2/3 Ni_1/3 Mn_{2/3- x} Ti_x O₂ (x = 0, 1/6, 1/3, 2/3) is demonstrated. The X-ray diffraction (XRD) Rietveld refinement and aberration-corrected scanning transmission electron microscopy show the co-existence of P3 and O3 phases, and density functional theory calculation corroborates the appearance of the anomalous O3 phase at the Ti substitution amount of 1/3. The P3/O3 biphasic cathode delivers an unexpected rate capability (≈88.7% of the initial capacity at a high rate of 5 C) and cycling stability (≈68.7% capacity retention after 2000 cycles at 1 C), superior to those of the sing phases P3-Na_2/3 Ni_1/3 Mn_2/3 O₂ , P3-Na_2/3 Ni_1/3 Mn_1/2 Ti_1/6 O₂ , and O3-Na_2/3 Ni_1/3 Ti_2/3 O₂ . The highly reversible structural evolution of the P3/O3 integrated cathode observed by ex situ XRD, ex situ X-ray absorption spectra, and the rapid Na⁺ diffusion kinetics, underpin the enhancement. These results show the important role of P3/O3 biphasic hybridization in designing and engineering layered oxide cathodes for NIBs.

Elucidating the Redox Behavior in Different P-type Layered Oxides for Sodium-Ion Batteries

Sodium layered transition-metal oxides have attracted great attention for advanced Na-ion batteries (NIBs) because of their rich structural diversity and superior specific capacity provided by not only cation redox reactions but also possible oxygen-related anionic redox reactions. However, they usually undergo severe electrochemical performance fading, especially the voltage retention during the cationic and anionic redox processes. Herein, we design and synthesize a couple of novel sodium lithium magnesium aluminum manganese oxides (Na_0.75Li_0.2Mg_0.05Al_0.05Mn_0.7O₂) with the same Na⁺ coordination environment but different oxide layer stacking sequences, namely, P2-NLMAMO and P3-NLMAMO. We systematically investigate and compare the voltage decay phenomenon and the cationic/anionic redox processes under different electrochemical cycling windows combined with ex situ hard and soft X-ray absorption spectroscopy techniques. The results clearly indicate that the P2-NLMAMO electrode with a lower extent of Mn redox is prone to deliver a superior capacity retention and rate performance, more importantly, a higher average voltage in contrast to the P3-type counterpart. In addition, negligible change is detected for the average discharge voltage upon extended cycling when increasing the discharge cutoff voltage to 2.5 V for both P2-NLMAMO and P3-NLMAMO. This unique feature work provides an effective strategy for developing high-capacity P-type layered cathodes based on both cationic and anionic redox chemistry under controlled crystal structure arrangement, which could lead to a deeper understanding of the correlation between crystal structure and electrochemical performance for NIBs.

Deciphering the Structure-Property Relationship of Na-Mn-Co-Mg-O as a Novel High-Capacity Layered-Tunnel Hybrid Cathode and Its Application in Sodium-Ion Capacitors

Developing novel cathode materials with a high energy density and long cycling stability is necessary for Na-ion batteries and Na-ion hybrid capacitors (NICs). Despite their high energy density, structural flexibility, and ease of synthesis, P-type Na layered oxides cannot be utilized in energy-storage applications owing to their severe capacity fading. In this regard, we report a novel composite layered-tunnel Na_0.5Mn_0.5Co_0.48Mg_0.02O₂ cathode whose binary structure was confirmed via scanning electron microscopy and high-resolution transmission electron microscopy. Combination of the two-dimensional (2D) layered oxides with the three-dimensional tunnel structure, as well as the presence of Mg²⁺ ions, resulted in a high capacity of 145 mAh g^-1 at a current density of 85 mA g^-1, along with a high stability and rate capability. An NIC was fabricated with composite layered-tunnel structure as a battery-type electrode and commercial activated carbon as a counter electrode. The NIC exhibited a maximum energy density of 35 Wh kg^-1 and good stability retaining 72% of its initial energy density after 3000 cycles. This integrated approach provides a new method for designing high-energy and high-power cathodes for NICs and NIBs.