Flexible solid-state zinc-ion battery is promising energy technology with low cost, excellent performance, and safety. However, the mechanical properties of flexible electrolytes are severely limited. Here, hydroxyethyl cellulose (HEC) and montmorillonite (MMT) were introduced into a polyvinyl alcohol (PVA) matrix to prepare a novel composite hydrogel using a repeated freeze-thaw method. Both organic HEC and inorganic MMT could form hydrogen bonds with PVA molecular chains, acting as crosslinkers to construct a well-networked hydrogel structure. The synergistic effect of these two crosslinkers significantly enhanced the mechanical properties of the composite hydrogel. The composite hydrogel prepared with 3 wt% HEC and 2 wt% MMT (denoted as –H-M) exhibited a 242.6% increase in tensile strength, 78.6% increase in elongation at break, and 970.1% increase in compressive strength compared to pure PVA hydrogel. –H-M hydrogel also demonstrated a high electrolyte uptake rate (199.15%) and ion conductivity (24.6 mS cm). When assembled in a Zn symmetric battery, it maintained stable operation for 3000 h with a low polarization voltage of approximately 70 mV. Furthermore, –H-M hydrogel assembled in a Zn//MnO battery exhibited a discharge specific capacity of 218 mAh g at a current density of 0.15 A g, with 91% capacity retention after 450 cycles. At a higher current density of 1.5 A g, it showed a discharge specific capacity of 108 mAh g, which is 4.5 times higher than that of the PVA hydrogel battery, demonstrating excellent rate performance.

中文翻译：

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羟乙基纤维素与蒙脱土的协同交联作用对聚乙烯醇水凝胶力学和电化学性能改善的影响

柔性固态锌离子电池是一种成本低廉、性能优良、安全可靠的有前景的能源技术。然而，柔性电解质的机械性能受到严重限制。在此，将羟乙基纤维素（HEC）和蒙脱土（MMT）引入聚乙烯醇（PVA）基质中，采用反复冻融方法制备新型复合水凝胶。有机HEC和无机MMT均可与PVA分子链形成氢键，作为交联剂构建良好网络化的水凝胶结构。这两种交联剂的协同作用显着增强了复合水凝胶的机械性能。与纯PVA水凝胶相比，用3wt%HEC和2wt%MMT（记为-HM）制备的复合水凝胶的拉伸强度增加了242.6%，断裂伸长率增加了78.6%，压缩强度增加了970.1%。 –HM水凝胶还表现出高电解质吸收率（199.15%）和离子电导率（24.6 mS cm）。当组装在锌对称电池中时，它可以稳定运行3000小时，极化电压约为70 mV。此外，组装在Zn//MnO电池中的-HM水凝胶在0.15 A g-1的电流密度下表现出218 mAh g-1的放电比容量，450次循环后容量保持率为91%。在1.5 A g-1的较高电流密度下，其放电比容量为108 mAh g-1，是PVA水凝胶电池的4.5倍，表现出优异的倍率性能。