Boosting high-rate lithium storage in Li3VO4via a honeycomb structure design and electrochemical reconstruction

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 11; no. 23; pp. 12164 - 12175
• Main Authors: Bai, Xiaomeng, Li, Daobo, Zhang, Dongmei, Yang, Song, Cunyuan Pei, Sun, Bing, Ni, Shibing
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 13.06.2023
• Subjects: Constituents; Cycles; Discharge; Electric vehicles; Electrochemistry; Electrodes; Electron transfer; Honeycomb structures; Ion diffusion; Life span; Lithium; Nanoparticles; Performance tests; Polyvinyl alcohol; Power plants; Reconstruction; Self-assembly; Synergistic effect; Void space
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d3ta01817b

While the intrinsic safety and capacity merits of Li3VO4 endow it with great promise in LIBs, the moderate lifespan under a high rate hinders its practical application. Herein, we demonstrate for the first time, the boosting of an unprecedented high-rate performance of the Li3VO4-based electrode via a novel honeycomb architecture design and its electrochemical reconstruction upon cycling. Li3VO4/C honeycombs (LVO/C Hs) consisting of primary carbon-coated Li3VO4 nanoparticles have been constructed by a self-assembly strategy, through a developed electrospraying approach using polyvinyl alcohol as a morphology regulator. In the LVO/C Hs, the local LVO@C nanoparticle constituents render high activity, and the integral honeycomb-like architecture facilitates electron transfer and promotes a synergistic effect between the constituents. The lithiation-driven electrochemical reconstruction in cycling ensures the integrity of the honeycomb structure, and at the same time, the LVO nanoparticles are refined to 3–5 nm, producing abundant nanopores. The self-reconfigured structures with ultrasmall nanoparticles and large void space effectively shorten the ion diffusion pathway. The above structural characteristics trigger a continuous high capacitive charge storage, giving rise to unprecedented high-rate performance. The LVO/C Hs electrode delivered a discharge capacity recovery of 590.0 mA h g−1 at 0.5 A g−1 after 6 periodic rate performance tests from 0.5 to 10 A g−1 over 430 cycles. When cycling at a high discharge current of 6 A g−1, the LVO/C Hs electrode could maintain stable cycling over 14 000 cycles with a high discharge capacity of 324.5 mA h g−1. The lifespan of the LVO/C Hs is the longest among all the reported LVO-based electrodes, demonstrating great potential in long-life and high-rate applications such as electric vehicles and power stations.