Dilithium phthalocyanine as electrolyte additive for the regulation of ion solvation and transport towards dendrite-free Li metal anodes
Dilithium phthalocyanine as electrolyte additive for the regulation of ion solvation and transport towards dendrite-free Li metal anodes
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DOI：
10.1016/j.cej.2022.138112
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发表时间：
2022
影响因子：
15.1
通讯作者：
Cheng Hu
中科院分区：
文献类型：
--
作者：
Xuting Li;Zhanghua Fu;Jing Wang;Xinhong Zhao;Yukun Zhang;Weizhe Liu;Qiong Cai;Cheng Hu
• Dilithium Phthalocyanine modifies ion solvation and transport at a low addition. • Phthalocyanine ligand weakens the dipole-dipole interactions of the solvents. • Improved anion-dipole interactions suppress the mobility of the anions. • High ionic conductivity and Li + transference number are achieved. • Stable and dendrite-free Li-metal anodes and Li-S full cells are demonstrated. The application of Li metal anodes in high energy-density batteries is hindered by the uncontrolled dendrite growth and rapid capacity fading. Herein, we demonstrate that dilithium phthalocyanine (Li 2 Pc) is highly effective for the regulation of ion solvation and transport towards dendrite-free Li metal anodes. The strong interactions of Li 2 Pc with the solvents generate an apparent solvation sheath surrounding the large phthalocyanine ligand, where the dipole-dipole interactions of the solvents are weakened. This promotes the anion solvation in the outer solvation sheath, which suppresses the mobility of the anions for apparently increased Li + transference number and facilitates the dissociation of the solute for a higher ionic conductivity. The resulting uniform Li + flux alleviates the space charge to impede the growth of dendrites. Stable Li plating/stripping of 800 h (1 mA cm -2 , 1 mAh cm -2 ) and dendrite-free Li deposition up to 10 mA cm -2 , 10 mAh cm -2 are achieved in Li/Li cells and the Li/Cu cells exhibit a high average CE of 98.3% over 150 cycles at 1 mA cm -2 , 1 mAh cm -2 . Stable cycling of Li-S full cells at the condition of N:P=2:1 are also demonstrated with high average CEs of 98.29%.
