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
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Institute of Fiber Materials and Devices, Fudan University, Shanghai, China.
Research Center of AI for Polymer Science, Laboratory of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University, Shanghai, China.
Nature. 2025 Feb;638(8051):676-683. doi: 10.1038/s41586-024-08465-y. Epub 2025 Feb 12.
Lithium (Li) ions are central to the energy storing functionality of rechargeable batteries. Present technology relies on sophisticated Li-inclusive electrode materials to provide Li ions and exactingly protect them to ensure a decent lifetime. Li-deficient materials are thus excluded from battery design, and the battery fails when active Li ions are consumed. 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 (LiSOCF) with optimal electrochemical activity, potential, product formation, electrolyte solubility and specific capacity. As a proof-of-concept, we demonstrated a 3.0 V, 1,192 Wh kg Li-free cathode, chromium oxide, in the anode-less cell, as well as an organic sulfurized polyacrylonitrile cathode incorporated in a 388 Wh kg 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 LiFePO batteries was extended by at least an order of magnitude. With repeated external Li supplies, a commercial graphite|LiFePO cell displayed a capacity retention of 96.0% after 11,818 cycles.
锂离子对于可充电电池的能量存储功能至关重要。目前的技术依赖于复杂的含锂电极材料来提供锂离子，并严格保护它们以确保有良好的使用寿命。因此，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。我们的研究通过一种电池级锂供应策略打破了这一限制。这包括在组装好的电池外部添加一种有机锂盐，该盐在电池形成过程中分解，释放出锂离子并将有机配体以气体形式排出。这个非侵入性的快速过程保持了电池的完整性，无需拆卸。我们利用机器学习发现了这种功能性盐，并确定了具有最佳电化学活性、电位、产物形成、电解质溶解度和比容量的三氟甲磺酸锂（LiSOCF）。作为概念验证，我们在无阳极电池中展示了一个3.0 V、1,192 Wh kg的无锂阴极氧化铬，以及在一个具有440次循环寿命的388 Wh kg软包电池中使用的有机硫化聚丙烯腈阴极。与传统锂离子电池相比，这些系统具有更高的能量密度、更强的可持续性和更低的成本。此外，商用磷酸铁锂（LiFePO）电池的寿命至少延长了一个数量级。通过反复外部供应锂，一个商用石墨|磷酸铁锂电池在11,818次循环后容量保持率为96.0%。
