Ultrahigh‐Rate and Ultralong‐Duration Sodium Storage Enabled by Sodiation‐Driven Reconfiguration

Abstract

paring to the scarce and nonuniform distributed lithium. [1] However, in practical applications, SIBs suffer from low capacity and poor rate performance owning to the large ionic radius of Na-ion. [2,3] Typically, to improve the electrochemical performance of SIBs during charge/discharge processes, different materials have been developed as anode electrodes for SIBs, including various carbonaceous materials, transition metal compounds and so on. [4,5] Among these, carbonaceous materials have limited capacities due to their poor storage capability for Na-ion, while transition metal compounds (TMDs) can make up these shortages and exhibit ideal theoretical specific capacities. [6,7] Vanadium sulfides (VS x ), with various crystal structures, such as VS 2 , V 2 S 3 , V 3 S 4 , V 5 S 8 and VS 4 have attracted increasing attention because they could offer proper interlayer spacing to accommodate Na + ions and have both intercalation/deintercalation and conversion energy storage processes. [8][9][10][11][12][13][14][15] For example, VS 2 with a large interlayer spacing of 0.575 nm delivered a higher theoretical specific capacity of about 800 mAh g −1 (comparing to 372 mAh g −1 of graphite anode in commercialized LIBs), suggesting that vanadiumbased sulfides could be a good candidate for SIBs. [11] Nevertheless, such vanadium-based sulfides frequently suffer significant mechanical pulverization during long-term cycling as a result of volume expansion caused by sodization/desodization, which results in severe irreversible capacity degradation and unsatisfactory cycling performance. [16,17] Up to now, the best (and one of the very few) cycling performance of all vanadium sulfides is V 5 S 8 /C electrode with 4000 cycles but only with a low specific capacity of 340 mAh g −1 (at 2 A g −1 ). [14] The best capacity performance so far of all vanadium sulfides is VS 4 -CN-Hs with 863 mA h g −1 at 0.1 A g −1 but only for 30 cycles. [15] Therefore, developing high-performance vanadium sulfide anode with both high capacity (energy density) and good cycling performance presents a key challenge for commercializing this vanadium sulfide-anode SIBs.3D micro/nanostructuring of vanadium sulfide anode might provide a clue to address the above challenge. Such 3D micro/nanostructures have been approved for overcoming Despite their variable valence and favorable sodiation/desodiation potential, vanadium sulfides (VS x ) used as anode materials of sodium-ion batteries (SIBs) have been held back by their capacity decline and low cycling capability, associated with the structure distortion volume expansion and pulverization. This study reports an accessible process to tackle these challenges via fabricating a 3D-VS x anode for SIBs with ultrahigh-rate and ultralong-duration stable sodium storage. The sodiation-driven reactivation of micro-nano 3D-VS x activates the reconfiguration effect, effectively maintaining structural integrity. Interestingly, the mechanical degradation of 3D-VS x over the sodiation process can be controlled by fine-tunin...

CO2 Conversion Toward Real‐World Applications: Electrocatalysis versus CO2 Batteries

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Photoreaction Mechanism of the VS4-Biomass Carbon Bifunctional Electrode for Photorechargeable Batteries

“…The growth stage corresponds to the electrochemical activation process, which can boost the overall performance of rechargeable batteries. These results are much better than those of VS 4 , which may be due to the fact that the highly branched hierarchical flower-like structure of VS 4 -BC 0.02 can relieve volume expansion. , This viewpoint is also supported by the electrochemical impedance spectroscopy (EIS) of the three materials (Figure S6). The Nyquist plot of each electrode contains a semicircle and incline line.…”

Homologous Heterostructured NiS/NiS2@C Hollow Ultrathin Microspheres with Interfacial Electron Redistribution for High‐Performance Sodium Storage

“…The discharge capacity increases gradually in the early stage of sodiation/desodiation process, reaching 500.0 mA h g −1 at 708th cycle, it should be contributed to the activation of nanoparticles, copper foil involved in part of the embedded sodium reaction, and sodiation-driven reconfiguration. [67][68][69] After 4500 cycles, the discharge capacity of the H-NiS/NiS 2 @C can still reserve 433.4 mA h g −1 accompanied by the capacity decay rate of 0.0035% per cycle, and the Coulombic efficiencies are almost 100%. Unfortunately, the structure of the material is difficult to maintain at high current densities, after 1000 cycles the structure is destroyed (Figure S10a, Supporting Information) and after 1500 cycles (Figure S10b, Supporting Information) the structure collapses completely.…”