Journal of Materials Science: Materials in Electronics ( IF 2.8 ) Pub Date : 2024-01-13 , DOI: 10.1007/s10854-024-11940-x Di Ma , Hao He , Xinglan Huang , Jingcheng Wang , Xuebu Hu
The inhomogeneous plating/stripping of zinc and side reactions originating from the dissolution of the cathode material in water lead to the poor stability of zinc anode, which inevitably limits the practical application of zinc-based aqueous batteries. Therefore, a novel hydrogel electrolyte made of hydroxyethyl cellulose/polyacrylamide (HEC/PAM) with a 3D network-like structure is synthesized by radical polymerization and cross-linking reinforcement. Thanks to the porous crosslinked network and massive hydrophilic groups, the electrolyte has high ion conductivity of 3.17 × 10–2 S cm−2 and decomposition voltage of 2.6431 V. The ion conductive hydrophilic groups facilitate the interfacial compatibility of the electrode with the electrolyte and stabilize zinc plating/stripping, which suppresses the formation of zinc dendrites. Meanwhile, the hydrogel electrolyte effectively alleviates the dissolution of the positive electrode and the occurrence of side reactions, and subsequently improves the stability of the electrode. As a result, the assembled Zn–Zn symmetric cell with HEC/PAM hydrogel electrolyte is stable without short circuit and rapid increase of overvoltage at 5 mA cm−2. The polarization voltage of the assembled Zn–Cu half-cell is 59.2 mV and initial coulomb efficiency reaches 94.3%. The assembled Zn–V2O5·nH2O/CNT full cell delivers an excellent cycling stability of 186.9 mAh g−1 at 0.5 A g−1 after 500 cycles with a high-capacity retention of 92.5% (only 52.1% in aqueous system). The new idea is provided for further development of functional hydrogel electrolytes in zinc-ion batteries.
中文翻译:
HEC/PAM水凝胶电解质调节锌负极表面以抑制锌离子电池中的枝晶
锌的镀/剥不均匀以及正极材料在水中溶解产生的副反应导致锌负极稳定性差,这不可避免地限制了锌基水系电池的实际应用。因此,通过自由基聚合和交联增强,合成了一种由羟乙基纤维素/聚丙烯酰胺(HEC/PAM)制成的具有3D网络状结构的新型水凝胶电解质。由于多孔交联网络和大量亲水基团,电解质具有3.17 × 10 –2 S cm -2的高离子电导率和2.6431 V的分解电压。离子导电亲水基团促进了电极与电解质的界面相容性,并且稳定镀锌/剥镀,从而抑制锌枝晶的形成。同时,水凝胶电解质有效缓解了正极的溶解和副反应的发生,从而提高了电极的稳定性。结果,使用HEC/PAM水凝胶电解质组装的Zn-Zn对称电池在5 mA cm -2下稳定,没有短路和过电压快速增加。组装的Zn-Cu半电池的极化电压为59.2 mV,初始库仑效率达到94.3%。组装的Zn–V 2 O 5 ·nH 2 O/CNT全电池在0.5 A g -1下循环500次后具有186.9 mAh g -1的优异循环稳定性,并且容量保持率为92.5%(在0.5 A g -1 条件下,容量保持率仅为52.1%)。水系统)。该研究为进一步开发锌离子电池功能性水凝胶电解质提供了新思路。