Investigating structure evolution of near-zero strain lithium-rich cathode materials

Rapid capacity fade and voltage drop are the major problems for lithium-rich cathode materials. Through ion doping, surface coating and other means can effectively optimize the electrochemical performance. we synthesized a near-zero strain material through a dual-doping strategy to tackle the electrochemical performance degragation of Lithium-rich materials and enhance Li-ion diffusion kinetics. The aim of this proposal is to elucidate the structural and charge compensation degradation mechanism of this near-zero strain lithium-rich cathode materials. For this propose, samples cut-off at various voltages both before and after cycling are prepared for in-situ synchrotron X-ray diffraction (sXRD) via BM20 to investigate the effect of La-Ti dual-doping on the degradation of structure.

富锂正极材料（lithium-rich cathode materials）面临的核心问题为容量快速衰减与电压下降。离子掺杂、表面包覆等手段可有效优化其电化学性能。本研究采用双掺杂策略合成了近零应变材料，以解决富锂材料的电化学性能衰减问题，并提升锂离子扩散动力学。本研究旨在阐明该近零应变富锂正极材料的结构与电荷补偿衰减机制。为此，我们制备了循环前后不同截止电压下的样品，借助BM20线站开展原位同步辐射X射线衍射（in-situ synchrotron X-ray diffraction, sXRD）测试，以探究La-Ti双掺杂对材料结构衰减的调控作用。