钠电池电解液的粘度对低温性能有什么影响？

How does electrolyte viscosity affect the low-temperature performance of sodium-ion batteries?

电解液粘度与低温放电性能负相关，粘度越高低温衰减越剧烈。气温下降后溶剂分子运动减弱，电解液粘稠度飙升，钠离子通道堵塞，离子电导率断崖下跌，电芯内阻成倍上涨。高粘度电解液难以浸润极片微孔，大量储钠位点闲置，-20℃容量仅剩余常温 60%；同时离子分布不均诱发负极局部析钠，刺穿隔膜造成内部短路，存在起火隐患。低粘度电解液低温流动性优异，可稳定传导离子，保障低温启动与持续放电。行业解决方案混合低凝固点链碳酸酯、少量醚或羧酸酯，降低低温粘度，适配北方户用储能、户外工程机械、冷链设备，全年稳定输出容量，大幅拓宽电池适用温度区间。

Electrolyte viscosity is negatively correlated with low-temperature discharge performance, with higher viscosity bringing severe performance degradation. As temperature falls, solvent molecular motion weakens, viscosity surges, sodium channels get blocked, ionic conductivity plummets and cell resistance multiplies. High-viscosity electrolytes fail to infiltrate electrode micropores, leaving most storage sites idle, with capacity dropping to only 60% of room-temperature value at -20°C. Uneven ion distribution triggers local sodium precipitation on anodes, piercing separators and causing internal short circuits with fire risks. Low-viscosity electrolytes maintain excellent fluidity and stable ion conduction for cold start and continuous discharge. The industry blends low-freezing linear carbonates with small amounts of ethers or carboxylates to cut low-temperature viscosity, adapting to northern household storage, outdoor machinery and cold-chain equipment for stable year-round capacity output.