复旦大学高悦小组近日取得一项新成果。经过不懈努力，他们的研究发现外置锂电源改变了电池的锂不足和寿命限制。2025年2月12日出版的《自然》发表了这项成果。

该课题组研究人员利用机器学习来发现这些功能盐，并确定了具有最佳电化学活性、电势、产物形成、电解质溶解度和比容量的三氟甲烷磺酸锂（LiSO₂CF₃）。作为概念验证，课题组演示了3.0V, 1192Wh kg^-1无锂阴极，氧化铬，在无阳极电池，以及有机硫化聚丙烯腈阴极纳入388Whkg^-1电池，循环寿命440次。与传统锂离子电池相比，这些系统具有更高的能量密度、更高的可持续性和更低的成本。

此外，商用LiFePO₄电池的寿命至少延长了一个数量级。在重复的外部锂供应下，商用石墨|LiFePO₄电池在11818次循环后的容量保持率为96.0%。

研究人员表示，锂离子是可充电电池储能功能的核心。目前的技术依赖于复杂的锂离子电极材料来提供锂离子，并精确地保护它们，以确保它们的使用寿命。缺锂材料被排除在电池设计之外，当活性锂离子被消耗时，电池就会失效。他们的研究通过细胞级锂供应策略打破了这一限制。这包括在外部将有机锂盐添加到组装的细胞中，在细胞形成过程中分解，释放锂离子并以气体形式排出有机配体。这种非侵入性和快速的过程保持了细胞的完整性，而无需拆卸。

附：英文原文

Title: External Li supply reshapes Li deficiency and lifetime limit of batteries

Author: Chen, Shu, Wu, Guanbin, Jiang, Haibo, Wang, Jifeng, Chen, Tiantian, Han, Chenyang, Wang, Wenwen, Yang, Rongchen, Zhao, Jiahua, Tang, Zhihang, Gong, Xiaocheng, Li, Chuanfa, Zhu, Mengyao, Zhang, Kun, Xu, Yifei, Wang, Ying, Hu, Zhe, Chen, Peining, Wang, Bingjie, Zhang, Kai, Xia, Yongyao, Peng, Huisheng, Gao, Yue

Issue&Volume: 2025-02-12

Abstract: Lithium (Li) ions are central to the energy storing functionality of rechargeable batteries1. Present technology relies on sophisticated Li-inclusive electrode materials to provide Li ions and exactingly protect them to ensure a decent lifetime2. Li-deficient materials are thus excluded from battery design, and the battery fails when active Li ions are consumed3. Our study breaks this limit by means of a cell-level Li supply strategy. This involves externally adding an organic Li salt into an assembled cell, which decomposes during cell formation, liberating Li ions and expelling organic ligands as gases. This non-invasive and rapid process preserves cell integrity without necessitating disassembly. We leveraged machine learning to discover such functional salts and identified lithium trifluoromethanesulfinate (LiSO₂CF₃) with optimal electrochemical activity, potential, product formation, electrolyte solubility and specific capacity. As a proof-of-concept, we demonstrated a 3.0V, 1,192Whkg^-1 Li-free cathode, chromium oxide, in the anode-less cell, as well as an organic sulfurized polyacrylonitrile cathode incorporated in a 388Whkg^-1 pouch cell with a 440-cycle life. These systems exhibit improved energy density, enhanced sustainability and reduced cost compared with conventional Li-ion batteries. Furthermore, the lifetime of commercial LiFePO₄ batteries was extended by at least an order of magnitude. With repeated external Li supplies, a commercial graphite|LiFePO₄ cell displayed a capacity retention of 96.0% after 11,818 cycles.

DOI: 10.1038/s41586-024-08465-y

Source: https://www.nature.com/articles/s41586-024-08465-y