Operando pair distribution function analyses to determine the nature of the oxidized species of oxygen in an O2-type lithium rich layered ox

This proposal aims to study the local structural rearrangements that occur in O2-type lithium-rich layered manganese oxide during the first cycle of lithium electrochemical (de)intercalation. The O2-LiMn0.75O2 phase will be used as the positive electrode material in lithium-metal batteries. Total X-ray scattering intensities will be collected at the ID31 beamline from the O2-LiMn0.75O2 materials operando during the first charge and the discharge of the batteries. Pair distribution functions (PDFs) will then be calculated, which will allow the changes in the first oxygen-oxygen distances during cycling to be precisely monitored. This would help us to identify the nature of the oxidized species of oxygen (oxidized oxide ions O-, peroxo-like ions O22- or trapped O2 gas molecules) during the first charge.

本研究提案旨在探究O2型富锂层状锰氧化物（O2-type lithium-rich layered manganese oxide）在锂电化学(脱)嵌锂首循环过程中发生的局部结构重排。其中，O2-LiMn0.75O2相将被用作锂金属电池的正极材料。研究人员将在ID31光束线（ID31 beamline）上，对电池首圈充放电过程中的O2-LiMn0.75O2材料开展原位（operando）总X射线散射强度采集。后续将计算对分布函数（Pair Distribution Functions, PDFs），以此精准监测循环过程中氧-氧间距的变化。这将有助于明确首圈充电阶段氧氧化物种的具体类型，涵盖氧化态氧离子O⁻、过氧类离子O₂²⁻以及被俘获的O₂气体分子。