A Salt-in-Metal Anode: Stabilizing the Solid Electrolyte Interphase to Enable Prolonged Battery Cycling |
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Authors: | Lin Fu Xiancheng Wang Li Wang Mintao Wan Yuanjian Li Zhao Cai Yuchen Tan Guocheng Li Renming Zhan Zhi Wei Seh Yongming Sun |
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Affiliation: | 1. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074 China;2. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 China;3. Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore, 138634 Singapore |
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Abstract: | Metallic lithium (Li) is the ultimate anode candidate for high-energy-density rechargeable batteries. However, its practical application is hindered by serious problems, including uncontrolled dendritic Li growth and undesired side reactions. In this study a concept of “salt-in-metal” is proposed, and a Li/LiNO3 composite foil is constructed such that a classic electrolyte additive, LiNO3, is embedded successfully into the bulk structure of metallic Li by a facile mechanical kneading approach. The LiNO3 reacts with metallic Li to generate Li+ conductive species (e.g., Li3N and LiNxOy) over the entire electrode. These derivatives afford a stable solid electrolyte interphase (SEI) and effectively regulate the uniformity of the nucleation/growth of Li on initial plating, featuring a low nucleation energy barrier and large crystalline size without mossy morphology. Importantly, these derivatives combined with LiNO3 can in-situ repair the damaged SEI from the large volume change during Li plating/stripping, enabling a stable electrode-electrolyte interface and suppressing side reactions between metallic Li and electrolyte. Stable cycling with a high capacity retention of 93.1% after 100 cycles is obtained for full cells consisting of high-loading LiCoO2 cathode (≈20 mg cm−2) and composite metallic Li anode with 25 wt% LiNO3 under a lean electrolyte condition (≈12 µL) at 0.5 C. |
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Keywords: | LiNO3 lithium metal anodes mechanical kneading salt-in-metal solid electrolyte interphase |
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