弱溶剂化学助力水系锌金属电池在-50~80℃的宽温度范围内稳定运行

Weak solvent chemistry enables stable aqueous zinc metal batteries over a wide temperature range from-50 to 80℃

开发具有宽温度范围、无枝晶生长和耐腐蚀的电解质对于水系金属锌电池的实际应用至关重要.本研究开发了一种γ-戊内酯共溶剂,以扩大水系电解质的工作温度范围并稳定锌金属阳极的界面.这种弱溶剂作为强氢键配体和“稀释剂”,高效地打破了自由水分子之间的氢键,从而提高了电解液的温度耐受性和化学稳定性.同时,γ-戊内酯也可以吸附在阳极表面从而促进锌的成核和调节锌的生长织构,实现无枝晶的锌沉积.这种优化后的电解质可以使对称电池的寿命达到2160 h,并可以在-50~80℃的宽温度范围内稳定运行.相应的ZnⅡ活性炭电容器和ZnⅡ聚苯胺电池在8100和1600次循环后,容量保持率分别为92.5%和85%.这种弱溶剂调控氢键和锌离子的溶剂鞘的机制为先进的水系电解质的设计提供了新的见解.

The development of electrolytes with a wide temperature range,no dendrite growth and corrosion resistance is essential for the practical application of aqueous zinc metal batteries.Herein,γ-valerolactone is developed as the co-solvent to extend the operating temperature range of the aqueous electrolyte and stabilize the zinc metal anode interface.This weak solvent acts as a strong hydrogen bonding ligand and"diluent"to break the hydrogen bonds between free water molecules,thus enhancing the temperature tolerance and chemical stability of the electrolyte.Theγ-valerolactone can also be adsorbed on the anode surface to achieve a dendrite-free zinc deposition behavior by promoting zinc nucleation and regulating zinc growth texture.The optimized electrolyte enables the symmetric cell to deliver a cycle/rest life of 2160 h and operate stably over a wide temperature range of-50 to 80℃.The corresponding ZnⅡAC and ZnⅡPANI cells exhibit capacity retention of 92.5%and 85%after 8100 and 1600 cycles,respectively.This mechanism of weak solvent-regulated hydrogen bonding and solvent sheath provides new insights into the design of advanced aqueous electrolytes.