Slightly Li-enriched chemistry enabling super stable LiNi0.5Mn0.5O2 cathodes under extreme conditions

• DOI: 10.1039/d4sc03805c
• Publication Date: 2024-08-09T02:01:13Z
• Authors: Siqi Chen; Ping Zhang; Xin Zhou; Wenbin Wu; Xiaohong Liu; Yifeng Liu; Guilin Feng; Bin Zhang; Wangyan Xing; Meihua Zuo; Ping Zhang; Genpin Lv; Yao Xiao; Shixue Dou; Wei Xiang
• Keywords: Chemistry; 02 engineering and technology; 0210 nano-technology

High voltage/high temperature operation aggravates the risk of capacity attenuation and thermal runaway layered oxide cathodes due to crystal degradation interfacial instability. A combined strategy bulk regulation surface chemistry design is crucial handle these issues. Here, we present a simultaneous Li2WO4-coated gradient W-doped 0.98LiNi0.5Mn0.5O2·0.02Li2WO4 cathode through modulating content exotic dopant stoichiometric lithium salt during lithiation calcination. Benefiting from slightly Li-enriched induced by hetero-epitaxially grown Li2WO4 surface, demonstrates superior electrochemical performance LiNi0.49Mn0.49W0.02O2 WO3 coated 0.98LiNi0.5Mn0.5O2·0.02WO3 without phase. Specifically, when cycled in potential range 2.7-4.5 V at 30 °C, possesses high discharge 199.2 156.5 mA h g-1 0.1 5C retention 92.88% after 300 cycles 1C. Even cut-off voltage 4.6 V, it still retains 91.15% 200 1C °C. Compared with LiNi0.5Mn0.5O2, enhanced can be attributed its robust stable interface, inhibited lattice oxygen release, improved Li+ transport kinetics. Our work emphasizes significance modulation stabilizing hence unlocks vast possibilities for future design.