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Irreversible phase transition caused capacity fading has been considered as an obstacle for rechargeable batteries. An in-depth investigation of the irreversible phase transition is critical for understanding the reaction mechanism and developing advanced batteries. In this work, taking vanadium oxide and its alkali ion-stabilized intercalation compounds (A-V-O, A = Li, Na, K) as prototypes, utilizing operando characterizations, we discovered coupled discontinuous (interlayer)-continuous (intralayer) transitions in the stabilized multielectron intercalation cathodes. The highly ordered crystal of vanadium pentoxide irreversibly transfers to a disordered/amorphous structure after the first cycle, whereas A-V-O enables reversible discontinuous lattice transitions at the interlayer pathway for facilitating lithium diffusion. Among the A-V-O family, K-V-O, with the highest capacity retention, shows a coupled discontinuous-continuous transition, which exhibits a continuous transition and the minimum volume change at the V-O intralayer during lithium intercalation/deintercalation. These coupled discontinuous-continuous lattice transitions were captured for the first time in cathode materials. It implies that the suitable ion intercalation induced continuous intralayer transition inhibits the irreversible ion intercalation and phase transition. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous Zn‐ion batteries (ZIBs) have received incremental attention because of their cost‐effectiveness and the materials abundance. They are a promising choice for large‐scale energy storage applications. However, developing suitable cathode materials for ZIBs remains a great challenge. In this work, pioneering work on the designing and construction of aqueous Zn//Na0.33V2O5 batteries is reported. The Na0.33V2O5 (NVO) electrode delivers a high capacity of 367.1 mA h g−1 at 0.1 A g−1, and exhibits long‐term cyclic stability with a capacity retention over 93% for 1000 cycles. The improvement of electrical conductivity, resulting from the intercalation of sodium ions between the [V4O12]n layers, is demonstrated by single nanowire device. Furthermore, the reversible intercalation reaction mechanism is confirmed by X‐ray diffraction, Raman, X‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy analysis. The outstanding performance can be attributed to the stable layered structure and high conductivity of NVO. This work also indicates that layered structural materials show great potential as the cathode of ZIBs, and the indigenous ions can act as pillars to stabilize the layered structure, thereby ensuring an enhanced cycling stability. [ABSTRACT FROM AUTHOR]

Scroll-shape structures with adjustable space provide interlayer sliding to accommodate the volume changes, which are promising candidates for increasing the stability of lithium batteries (LBs). In this work, for the first time, novel vanadium oxide polygonal nanoscrolls (PNSs) are synthesized in solution through self-rolling, Ostwald ripening, and scroll-by-scroll processes. The PNSs are of various shapes (including triangle, quadrangle, pentagon, and so forth) and spiral-wrapped multiwall. When evaluated as cathode for LB, the vanadium oxide PNSs cathode exhibits largely enhanced cycling stability (capacity retention of 91.7% after 150 cycles at 0.1 A g-1 in 2.0-4.0 V) compared with those of nonscrolled nanobelts (40.0%) and nanowires (35.8%). Even at 1.0 A g-1, the PNSs cathode delivers high-rate long-life performance with capacity retention of 80.6% after 500 cycles. The unique polygonal nanoscroll structure is favorable for improving the cyclability and rate capability in energy storage applications as demonstrated here, and it will be interesting and has great potential for other related applications. [ABSTRACT FROM AUTHOR]

Constructing a self‐buffered nanostructure is demonstrated to be a facile and effective strategy to enhance lithium battery performance. On page 1773 L. Mai and team construct a novel polygonal nanoscroll (PNS) structure via the self‐rolling, Ostwald ripening and scroll‐by‐scroll mechanism. This novel PNS structure offers the robust outer wall and expandable inner space to buffer the swelling stress during Li+ ion intercalation/extraction, which effectively improves the cycling stability. [ABSTRACT FROM AUTHOR]

Abstract: The novel ultrathin pre-lithiated V6O13 nanosheets are prepared through a low-temperature exfoliation in argon followed by a secondary hydrothermal lithiation. The smallest electrochemical devices based on nanosheet cathodes are fabricated to in situ probe the intrinsic advantages of pre-lithiated nanosheets. Pre-lithiated nanosheets show one order of magnitude higher in electrical conductivity compared with non-lithiated nanosheets. The conductance of ultrathin pre-lithiated V6O13 nanosheets still remains at the same level after discharge process while that of ultrathin non-lithiated nanosheets decreases over two orders of magnitude. The electrochemical performances of nanosheet cathodes before and after pre-lithiation are compared to further demonstrate the enhancement of the pre-lithiation. Ultrathin pre-lithiated V6O13 nanosheet cathodes exhibit a high discharge capacity of 301 mAh g−1 at the current density of 100 mA g−1. At a higher current density of 1000 mA g−1, the capacity retention after 150 cycles of ultrathin V6O13 nanosheet cathodes is greatly improved from 46% to 98% after pre-lithiation. The enhanced electrical conductance, excellent discharge capacities and cycling performance demonstrate the great potential of ultrathin pre-lithiated V6O13 nanosheets in next-generation high-performance energy storage applications. [Copyright &y& Elsevier]