Nan Jingya, Sun Yue, Yang Fusheng, Zhang Yijing, Li Yuxi, Wang Zihao, Wang Chuchu, Wang Dingkun, Chu Fuxiang, Wang Chunpeng, Zhu Tianyu, Jiang Jianchun
Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Key Laboratory of Biomass Energy and Material, Jiangsu Province, Nanjing, 210042, Jiangsu, People's Republic of China.
Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, 210037, Jiangsu, People's Republic of China.
Nanomicro Lett. 2023 Nov 20;16(1):22. doi: 10.1007/s40820-023-01229-9.
Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety, mechanical and thermal stability and easy-to-direct stacking. Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness, high conductivity and intrinsic flexibility. However, the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors. Here, we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance. The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode. Meanwhile, the cooperative solvation of ZnCl and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures. More significantly, the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance, delivering high-energy density of 39 Wh kg at -60 °C with capacity retention of 98.7% over 10,000 cycles. With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte, the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at -60 °C. This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.
固态锌离子电容器因其安全性提高、机械和热稳定性良好以及易于直接堆叠，正成为大规模储能领域颇具潜力的候选者。水凝胶电解质因其环保、高导电性和固有的柔韧性，是一种颇具吸引力的固态电解质。然而，当前水凝胶电解质的电解质/电极界面接触和抗冻性能对于锌离子电容器的实际应用而言仍具有挑战性。在此，我们报道了一类兼具高界面粘附性和抗冻性能的水凝胶电解质。坚韧的水凝胶基质与化学锚固的协同作用使得水凝胶电解质与电极之间形成了良好粘附的界面。同时，ZnCl和LiCl混合盐的协同溶剂化作用使水凝胶电解质在低温下同时具有高离子导电性和机械弹性。更重要的是，基于这种水凝胶电解质的Zn||碳纳米管混合电容器展现出低温电容性能，在-60°C时可提供39 Wh kg的高能量密度，在10000次循环中容量保持率为98.7%。得益于良好粘附的电解质/电极界面和抗冻水凝胶电解质，Zn/Li混合电容器即使在-60°C下也能够承受动态变形，并在1000次拉伸循环下正常工作。这项工作为实现低温锌离子电容器的稳定运行提供了有力策略。
