近年來，鋰離子電池的蓬勃發展使其被應用在多種領域，也因此面臨了許多挑戰，而其中一個挑戰便是如何使鋰離子電池在低溫下保有良好的效能。在低溫中，鋰離子電池將會面臨許多挑戰，如離子傳導能力減弱，導離度下降、電解液黏度升高、鋰枝晶生長不平整等問題。因此本研究利用無陽極鋰金屬電池來做為快速評判電解液的方法，並透過減少EC的體積比例來改善其高黏度的問題，並添加酯基有機溶劑來改善導離度與黏度問題，接著再更進一步的優化電解的配方，來得到更佳的電化學效能。得1M LiPF6 FEC/TTE /EMC/MA (1:5:2:2) 能在室溫下循環20圈後仍有62.08%的電容保持率，並在低溫中循環10圈後具有68.79%的電容保持率，相較於商用電解液1M LiPF6 EC/EMC (5:5) 在低溫中的效能，10圈後27.09%的電容保持率有著大幅得提升。
但在實驗過程中，觀察到此款電解液有儲放的問題，因此將鹽類改用LiTFSI，成功改善儲放問題，並利用其特性配置成局部高濃度電解液，接著為了改善鋁箔腐蝕的問題添加具有正極保護性並且能夠提升電解液導離度和形成穩定SEI層的LiPO2F2來形成雙鋰鹽系統，最後得出的電解液1.3M LiTFSI+0.1M LPF在室溫下循環20圈具有53.82%的電容量保持率，而在低溫中循環10圈後仍保有51.77%的電容量保持率。雖然不及原本使用LiPF6的電解液，但在改善儲放問題的同時，其表現仍優於商用電解液，算是成功將局部高濃度雙鋰鹽系統電解液成功應用於低溫中。

The development of lithium-ion batteries has applied in various fields in recently years. However, how to enhance the performance of lithium-ion batteries at cryogenic temperature is one of the issues to be solved. Lithium-ion batteries still suffer from several barriers, such as low ionic conductivity, high viscosity, and Li dendrite growth.
In this work, we use the anode free lithium metal battery as the protocol of the evaluation standard. By changing the solvent volume ratio and adding ester-based organic solvent to improve the high viscosity problem and enhance the ionic conductivity. Then optimize the electrolyte and change the formula of the electrolyte to gain better electrochemical performance. We present the optimized electrolyte 1M LiPF6 FEC/TTE/EMC/MA (1:5:2:2) which capacity retention remain 62.08% for 20 cycles at the ambient temperature. Compared to the commercial electrolyte at cryogenic conditions, optimized electrolyte has higher capacity retention (68.79%) for 10 cycles.
By replacing the lithium salt to LiTFSI that could alleviate the unstable preservation of the electrolyte in the experimental procedure. Moreover, Adding LiPO2F2(LPF) as the dual-salt system. LPF could protect cathode material, improve the conductivity of electrolyte and form a stable SEI layer. In dual-salt system, the electrolyte 1.3M LiTFSI + 0.1M LPF has the best performance, the capacity retention could remain 53.82% for 20 cycles at ambient temperature and 51.77% for 10 cycles at cryogenic temperature. From the above electrochemical performance, we successfully established the localization high concentration dual-salt system in cryogenic temperature.

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