文献类型：期刊文献

英文题名：Influence Mechanism of Precursor Crystallinity on ElectrochemicalPerformance of LiFePO4/C Cathode Material

作者：Zhang, Ting[1,2];Lin, Sen[1,2];Yu, Jianguo[1,3]

机构：[1]East China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake R, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Minist Educ, Engn Res Ctr Salt Lake Resources Proc Engn, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China

年份：2022

卷号：61

期号：15

起止页码：5181

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20221712033733);WOS:【SCI-EXPANDED(收录号:WOS:000794256700015)】；

基金：This work was sponsored by the National Natural Science Foundation of China (21978094) and Shanghai Pujiang Program (2019PJD011).

语种：英文

外文关键词：Agglomeration - Cathodes - Charge transfer - Crystallinity - Dehydration - Electric discharges - Lithium compounds - Lithium-ion batteries - Molecular dynamics - Reduction - Sintering

摘要：Determining the impact of precursor properties is essential for the performance regulation of LiFePO4cathodematerial prepared by carbothermic reduction. In this study, FePO4with different crystallinities, as precursors, was obtained at variousprecalcinating temperatures and reduced to form LiFePO4/C to quantitatively investigate crystallinity'sinfluence. Thecharacterization and molecular dynamics (MD) simulation results showed that the crystallinity of FePO4increased markedlywith a higher dehydration temperature, while excessive sintering would occur at 700 degrees C, resulting in a severe particle aggregation.The electrochemical analysis manifested that FePO4crystallinity would not affect the cyclic stability of cathode materials, but amoderate dehydration temperature of the precursor could equip LiFePO4/C with the best performance via an excellent balancebetween crystallinity and charge transfer. The excessive sintering and low crystallinity both brought about obvious reduction to thedischarge capacity of LiFePO4/C such that the discharge capacity at a 0.1 C rate would decrease from the optimum of 151.8 mAhmiddotg-1to less than 121.0 mAhmiddotg-1and 141.0 mAhmiddotg-1for the precursors calcinated at 500 and 700 degrees C, respectively. Our work providesa clear understanding of the non-negligible role of FePO4crystallinity and a valid direction for the control of the electrochemicalperformances of LiFePO4.