Lithium-ion batteries (LIBs) are greatly limited in their practical application because of their poor cycle performance, low conductivity and volume expansion. Herein, molten salts (MSs) FeCl₃·6H₂O–NMP with low temperature via simple preparation are used as the anode material of LIBs for the first time to break through the bottleneck of LIBs. The good fluidity and high self-healing of FeCl₃·6H₂O–NMP effectively avoid the collapse and breakage of the structure. Based on this feature, the initial discharge specific capacity reached 770.28 mA h g⁻¹, which was more than twice that of the commercial graphite anode. After 200 cycles at a current density of 100 mA g⁻¹, the specific capacity did not decrease rather it was found to be higher than the initial discharge specific capacity, reaching 867.24 mA h g⁻¹. Besides, the good conductivity of MSs provides convenience for the removal and intercalation of Li⁺. The active H sites that can combine with lithium ions form LiH and provide capacity for LIBs. Density functional theory (DFT) calculation also provided theoretical proof for the mechanism of LIBs.

中文翻译：

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构建新型高自愈性水合金属熔盐作为锂离子电池负极材料

锂离子电池（LIB）由于其循环性能差、电导率低和体积膨胀等缺点，在实际应用中受到很大限制。在此，首次采用简单制备的低温熔盐（MSs）FeCl ₃ ·6H ₂ O–NMP作为锂离子电池负极材料，突破了锂离子电池的瓶颈。 FeCl ₃ ·6H ₂ O–NMP良好的流动性和高自愈性有效避免了结构的倒塌和破损。基于这一特性，首次放电比容量达到770.28 mA hg ^-1，是商用石墨负极的两倍多。在100 mA g ^-1电流密度下循环200次后，比容量没有下降，反而高于首次放电比容量，达到867.24 mA hg ^-1。此外，MS良好的导电性为Li ⁺的脱嵌提供了便利。活性H位点可以与锂离子结合形成LiH并为LIB提供容量。密度泛函理论（DFT）计算也为LIB的机理提供了理论证明。