Enhancing the Performance of LLO Through Vanadium Doping and Abundant Exposed (010) Planes in Secondary Particles

TL;DR

Researchers improved lithium-rich layered oxide battery material by doping it with vanadium and using specific crystal planes to enhance performance and stability.

Contribution

Vanadium doping and (010) plane exposure in LLO secondary particles significantly improve structural stability and electrochemical performance.

Findings

Vanadium doping forms strong V-O bonds that suppress irreversible oxygen loss in LLO.

1 mol% vanadium doping increases capacity retention from 74.5% to 86% after 140 cycles.

Exposed (010) planes in secondary particles enhance structural stability during cycling.

Abstract

Lithium-rich layered oxide (LLO) has received extensive attention from researchers due to its high initial discharge capacity (≥250 mAh g−1). However, defects such as its high initial irreversible capacity, voltage decay, and poor rate performance have severely limited its commercialization. These issues arise because the Li2MnO3 component in LLO is activated during the initial cycle, leading to the participation of lattice oxygen anions (O2−) in redox reactions. This results in irreversible oxygen loss (O2) and subsequent structural phase transitions. To address these challenges, this study focuses on Li1.2Ni0.13Co0.13Mn0.54O2 as the host material, utilizing abundant exposed (010) plane secondary particles and employing a vanadium (V) doping strategy to enhance electrochemical performance. The V forms strong V-O bonds with the lattice oxygen, effectively suppressing irreversible oxygen loss and improving structural stability. The results demonstrate that the LLO achieves the best electrochemical performance as the doping amount is 1 mol%, and the capacity retention improves from 74.5% (undoped) to 86% (V-doped) after 140 cycles at 0.5 C.

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