Chen Zong-Ju, Shen Tian-Yu, Xiao Xiong, He Xiu-Chong, Luo Yan-Long, Jin Zhong, Li Cheng-Hui
State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, Collaborative Innovation Center of Advanced Microstructures, MOE Key Laboratory of Mesoscopic Chemistry, MOE Key Laboratory of High Performance Polymer Materials and Technology, Jiangsu Key Laboratory of Advanced Organic Materials, Tianchang New Materials and Energy Technology Research Center, Research Institute of Green Chemistry and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, P. R. China.
College of Science, Nanjing Forestry University, Nanjing, Jiangsu, 210037, P. R. China.
Adv Mater. 2024 Dec;36(52):e2413268. doi: 10.1002/adma.202413268. Epub 2024 Nov 14.
Quasi-solid-state aqueous zinc ion batteries suffer from anodic zinc dendrite growth during plating/stripping processes, impeding their commercial application. The inhibition of zinc dendrites by high-modulus electrolytes has been proven to be effective. However, hydrogel electrolytes are difficult to achieve high modulus owing to their inherent high water contents. This work reports a hydrogel electrolyte with ultrahigh modulus that can overcome the growth stress of zinc dendrites through mechanical suppression effect. By combining wet-annealing, solvent-exchange, and salting-out processes and tuning the hydrophobic and crystalline domains, a hydrogel electrolyte is obtained with substantial water content (≈70%), high modulus (198.5 MPa), high toughness (274.3 MJ m), and high zinc-ion conductivity (28.9 mS cm), which significantly outperforms the previously reported poly(vinyl alcohol)-based hydrogels. As a result, the hydrogel electrolyte exhibits excellent dendrite-suppression effect and achieves stable performance in Zn||Zn symmetric batteries (1800 h of cycle life at 1 mA cm). Moreover, the Zn||VO pouch batteries display excellent cycling life and operate stably even under extreme conditions, such as large bending angle (180°) and automotive crushing. This work provides a promising approach for designing mechanically reliable hydrogel electrolytes for advanced aqueous zinc ion batteries.
准固态水系锌离子电池在电镀/剥离过程中存在阳极锌枝晶生长问题，这阻碍了它们的商业应用。高模量电解质对锌枝晶的抑制作用已被证明是有效的。然而，水凝胶电解质由于其固有的高含水量而难以实现高模量。这项工作报道了一种具有超高模量的水凝胶电解质，它可以通过机械抑制作用克服锌枝晶的生长应力。通过结合湿退火、溶剂交换和盐析过程，并调整疏水和结晶域，获得了一种水凝胶电解质，其具有大量的含水量（约70%）、高模量（198.5兆帕）、高韧性（274.3兆焦/立方米）和高锌离子电导率（28.9毫西门子/厘米），显著优于先前报道的基于聚乙烯醇的水凝胶。结果，该水凝胶电解质表现出优异的枝晶抑制效果，并在Zn||Zn对称电池中实现了稳定的性能（在1毫安/平方厘米下循环寿命为1800小时）。此外，Zn||VO软包电池表现出优异的循环寿命，即使在大弯曲角度（180°）和汽车碾压等极端条件下也能稳定运行。这项工作为设计用于先进水系锌离子电池的机械可靠的水凝胶电解质提供了一种有前景的方法。
