{"title":"Targeted Defect Repair and Multi-functional Interface Construction for the Direct Regeneration of Spent LiFePO<sub>4</sub> Cathodes.","authors":"Yang Cao, Junfeng Li, Di Tang, Fei Zhou, Mengwei Yuan, Yanfei Zhu, Chengzhi Feng, Ruyu Shi, Xijun Wei, Boran Wang, Yingze Song, Hui-Ming Cheng, Guangmin Zhou","doi":"10.1002/adma.202414048","DOIUrl":null,"url":null,"abstract":"<p><p>Due to the low economic benefits and environmental pollution of traditional recycling methods, the disposal of spent LiFePO<sub>4</sub> (SLFP) presents a significant challenge. The capacity fade of SLFP cathode is primarily caused by lithium loss and formation of a Fe (III) phase. Herein, a synergistic repair effect is proposed to achieve defect repair and multi-functional interface construction for the direct regeneration of SLFP. Tannic acid (TA) forms a compact coating precursor for a carbon layer on SLFP with abundant functional groups and creates a mildly acidic environment to enhance the reducibility of thiourea (TU). Therefore, TU reduces Fe (III) to Fe (II) and repairs Li-Fe anti-site defects of SLFP, while at the same time acting as a source of N/S-doping elements for the carbon layer at a lower temperature (140 °C). The multi-functional carbon layer improves the properties of the regenerated LiFePO<sub>4</sub> (RLFP) due to the enhanced conductivity, structure maintenance and protection, and the improved kinetics of Li<sup>+</sup> transport. Furthermore, the Fe─O and P─O bonds are strengthened, further enhancing the structural stability of the RLFP. Consequently, the RLFP demonstrates outstanding performance with a discharge capacity of 141.3 mAh g<sup>-1</sup> and capacity retention of 72% after 1000 cycles at 1 C.</p>","PeriodicalId":114,"journal":{"name":"Advanced Materials","volume":null,"pages":null},"PeriodicalIF":27.4000,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1002/adma.202414048","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Due to the low economic benefits and environmental pollution of traditional recycling methods, the disposal of spent LiFePO4 (SLFP) presents a significant challenge. The capacity fade of SLFP cathode is primarily caused by lithium loss and formation of a Fe (III) phase. Herein, a synergistic repair effect is proposed to achieve defect repair and multi-functional interface construction for the direct regeneration of SLFP. Tannic acid (TA) forms a compact coating precursor for a carbon layer on SLFP with abundant functional groups and creates a mildly acidic environment to enhance the reducibility of thiourea (TU). Therefore, TU reduces Fe (III) to Fe (II) and repairs Li-Fe anti-site defects of SLFP, while at the same time acting as a source of N/S-doping elements for the carbon layer at a lower temperature (140 °C). The multi-functional carbon layer improves the properties of the regenerated LiFePO4 (RLFP) due to the enhanced conductivity, structure maintenance and protection, and the improved kinetics of Li+ transport. Furthermore, the Fe─O and P─O bonds are strengthened, further enhancing the structural stability of the RLFP. Consequently, the RLFP demonstrates outstanding performance with a discharge capacity of 141.3 mAh g-1 and capacity retention of 72% after 1000 cycles at 1 C.
期刊介绍:
Advanced Materials, one of the world's most prestigious journals and the foundation of the Advanced portfolio, is the home of choice for best-in-class materials science for more than 30 years. Following this fast-growing and interdisciplinary field, we are considering and publishing the most important discoveries on any and all materials from materials scientists, chemists, physicists, engineers as well as health and life scientists and bringing you the latest results and trends in modern materials-related research every week.