Wadsley–Roth Crystallographic Shear Structure Niobium‐Based Oxides: Promising Anode Materials for High‐Safety Lithium‐Ion Batteries

Abstract

Wadsley–Roth crystallographic shear structure niobium‐based oxides are of great interest in fast Li+ storage due to their unique 3D open tunnel structures that offer facile Li+ diffusion paths. Their moderate lithiation potential and reversible redox couples hold the great promise in the development of next‐generation lithium‐ion batteries (LIBs) that are characterized by high power density, long lifespan, and high safety. Despite these outstanding merits, there is still extensive advancement space for further enhancing their electrochemical kinetics. And the industrial feasibility of Wadsley–Roth crystallographic shear structure niobium‐based oxides as anode materials for LIBs requires more systematic research. In this review, recent progress in this field is summarized with the aim of realizing the practical applications of Wadsley–Roth phase anode materials in commercial LIBs. The review focuses on research toward the crystalline structure analyses, electrochemical reaction mechanisms, modification strategies, and full cell performance. In addition to highlighting the current research advances, the outlook and perspective on Wadsley–Roth anode materials is also concisely provided.

Single‐Crystal Nano‐Subunits Assembled Accordion‐Shape WNb2O8 Framework with High Ionic/Electronic Conductivities towards Li‐Ion Capacitors

“…[27] Noteworthy, the niobium-tungsten oxides with the tetragonal tungsten bronze (TTB) structure show potential applications for lithium storage due to its unique open multichannel structure. [28] In 2018, J. Griffith et al reported two micron-sized TTB structures (i.e., Nb 16 W 5 O 55 and Nb 18 W 16 O 93 ), which exhibited excellent rate properties due to rapid solid-state lithium transport, and a volume expansion of ≈2.8% over the charge/discharge process. [29] In 2020, Zhou and co-authors synthesized the TBB-structured WNb 2 O 8 (WNO) nanorods as an anode material for LIBs, however, the structural advantages and intrinsic Li-storage mechanism of WNO are not explored.…”

Synchronous Manipulation of Ion and Electron Transfer in Wadsley–Roth Phase Ti‐Nb Oxides for Fast‐Charging Lithium‐Ion Batteries

“…[1] Nevertheless, the underlying issues of Li plating and particle cracking for conventional graphite anodes under high charging rates severely impede the enhancement of XFC performance. [2] TiO 2 has been widely investigated as one of high-rate anode candidates due to its high theoretical capacity (≈335.4 mAh g −1 based on one electron transfer of Ti 4+ /Ti 3+ redox couple) and safe lithiation potential (1.5-1.8 V vs Li + /Li). However, the sluggish electrochemical kinetics resulting from intrinsically low electronic conductivity (≈10 −12 S cm −1 ) and Li + diffusion coefficient (≈10 −15 cm 2 s −1 ) impede its practical application.…”

Shear-structured MoNb6O18 as a new anode for lithium-ion batteries

“…[17] Recently, niobium-based oxides have been extensively investigated as high-rate anode materials for LIBs, due to their high theoretical capacities based-on multielectron reactions, fast lithium ion transport, most importantly, secure operating voltage (above 1.0 V vs Li + /Li) for safety features. [18][19][20] Therefore, niobium-based oxides anodes are promising candidates for high-powder LIBs anodes, specific in EV. [21] Most of niobiumbased oxides adopt Wadsley-Roth crystallographic shear structure with blocks consisting of distorted MO 6 octahedra sharing corners, and built of n × m × ∞ ReO 3 -type units (n and m are the numbers of MO 6 octahedra along the length and width of the blocks).…”

“…[22] This unique open tunnel structures can facile lithium ions diffusion and enhance lithium storage capacities. [19] Recently, Wadsley-Roth shear structure niobiumbased oxides, including W 5 Nb 16 O 55 [23] , MoNb 12 O 33 [24] , WNb 12 O 33 [25] , Mo 3 Nb 14 O 44 [26] , W 3 Nb 14 O 44 [27] , TiNb 2 O 7 [28] , Ti 2 Nb 10 O 29 [29] , have been investigated as high rate anode materials for LIBs. Mo-Nb-O oxides with Wadsley-Roth shear structure anode materials have shown great potential for highrate lithium ion storage.…”