Dramatic growth of lithium dendrite, structural deterioration of LiCoO₂ (LCO) cathode at high voltages, and unstable electrode/electrolyte interfaces pose significant obstacles to the practical application of high-energy-density LCO||Li batteries. In this work, a novel eutectogel electrolyte is developed by confining the nonflammable eutectic electrolyte in a polymer matrix. The eutectogel electrolyte can construct a robust solid electrolyte interphase (SEI) with inorganic-rich LiF and Li₃N, contributing to a uniform Li deposition. Besides, the severe interface side reactions between LCO cathode and electrolyte can be retarded with an in situ formed protective layer. Correspondingly, Li||Li symmetrical cells achieve highly reversible Li plating/stripping over 1000 h. The LCO||Li full cell can maintain 72.5% capacity after 1500 cycles with a decay rate of only 0.018% per cycle at a high charging voltage of 4.45 V. Moreover, the well-designed eutectogel electrolyte can even enable the stable operation of LCO at an extremely high cutoff voltage of 4.6 V. This work introduces a promising avenue for the advancement of eutectogel electrolytes, the nonflammable nature and well-regulated interphase significantly push forward the future application of lithium metal batteries and high-voltage utilization of LCO cathode.

中文翻译：

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Eutectogel 电解质为高压安全锂金属电池构建稳健的接口

_{锂枝晶的急剧生长、LiCoO 2} (LCO)正极在高电压下的结构恶化以及不稳定的电极/电解质界面对高能量密度LCO||Li电池的实际应用构成了重大障碍。在这项工作中，通过将不可燃的共晶电解质限制在聚合物基质中，开发了一种新型共晶凝胶电解质。共析凝胶电解质可以与富含无机物的LiF和Li ₃ N构建坚固的固体电解质界面（SEI），从而有助于均匀的Li沉积。此外，通过原位形成的保护层可以延缓LCO阴极和电解质之间严重的界面副反应。相应地，Li||Li对称电池在1000小时内实现了高度可逆的Li电镀/剥离。 LCO||Li全电池在4.45V的高充电​​电压下，循环1500次后容量仍保持在72.5%，每次循环衰减率仅为0.018%。此外，精心设计的共晶电解质甚至可以使LCO稳定运行。在4.6 V的极高截止电压下。这项工作为共熔凝胶电解质的发展提供了一条有前途的途径，其不可燃性和良好调节的界面显着推动了锂金属电池的未来应用和LCO阴极的高电压利用。