文献类型：期刊文献

英文题名：Dual-Carbon-Coated Na2FeP2O7 Cathode Materials for Na-Ion Batteries with Superior High-Rate and Cycling Stability

作者：Zhou, Linlin[1];Yu, Haifeng[2];Zhou, Bin[1];Yu, Jinxun[1];Chen, Ling[1];Jiang, Hao[1,2]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Key Lab Ultrafine Mat, Minist Educ, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Shanghai Engn Res Ctr Hierarch Nanomat, Sch Chem Engn, Shanghai 200237, Peoples R China

年份：2024

卷号：5

期号：9

外文期刊名：ADVANCED ENERGY AND SUSTAINABILITY RESEARCH

收录：EI(收录号：20242516267504);WOS:【ESCI(收录号:WOS:001248853400001)】；

基金：This work was supported by the National Natural Science Foundation of China (grant no. 22208102), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：cathode materials; cycling stability; Na2FeP2O7; Na-ion batteries

摘要：The iron-based pyrophosphate Na2FeP2O7 (NFP) is considered as one of the most promising cathodes for sodium-ion batteries (SIBs) due to its low-cost and superior structure stability, yet it usually suffers from poor intrinsic electronic conductivity. Herein, a two-step carbon-coating technique has been developed to synthesize high-performance NFP@C cathode materials by controlling the NFP particle size and the coating layer uniformity. The first step of in-situ carbon coating greatly restrains the excessive growth of NFP crystals with a shortened Na-ion diffusion path. Meantime, the extra secondary carbon-coating is adopted to repair some exposed areas, guaranteeing the full coverage of NFP particles for rapid electronic transfer. As a consequence, the as-obtained NFP@C cathode delivers a high discharge capacity of 95.2 mAh g(-1) at 0.1 C (theoretical value: 97 mAh g(-1)) and with high-rate capability (75.2 mAh g(-1 )at 5 C) within 2.0-4.0 V. A capacity retention of 95.3% can be achieved even after 500 cycles at 5 C in coin-type cells. Such superior electrochemical performances are expected to quickly promote the applications of NFP in SIBs.