Xie Dongmei, Zhao Jiachang, Jiang Qiong, Wang Hao, Huang Haiji, Rao Pinhua, Mao Jianfeng
College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, PR China.
School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia.
Chemphyschem. 2022 Sep 5;23(17):e202200106. doi: 10.1002/cphc.202200106. Epub 2022 Jun 29.
The binder is an indispensable battery component that maintains the integrity of the electrode. Polyvinylidene fluoride (PVDF) is most commonly used as a binder in rechargeable batteries; however, it is associated with the toxic and expensive N-methyl-2-pyrrolidone organic solvent. Here, through the cross-linking of sodium alginate (SA) with metal cations, a high-performance hydrogel binder is developed that maintains the stability of MnO cathodes in an aqueous electrolyte. Owing to the strong adhesion, high hydrophilicity, and good mechanical stability resulting from the strong bonding of Ca with SA, a commercial microsized MnO cathode with a Ca-SA binder delivered a capacity above 300 mAh/g at 1 C, which was larger than those of Mn-SA and Zn-SA (∼200 mAh/g) and PVDF (∼150 mAh/g) binders, and a capacity of 250 mAh/g at 3 C for over 200 cycles. These encouraging results could unlock the enormous potential of aqueous binders for practical applications in aqueous batteries.
粘结剂是维持电极完整性的不可或缺的电池组件。聚偏氟乙烯（PVDF）是可充电电池中最常用的粘结剂；然而，它与有毒且昂贵的N-甲基-2-吡咯烷酮有机溶剂有关。在此，通过海藻酸钠（SA）与金属阳离子的交联，开发出一种高性能水凝胶粘结剂，该粘结剂可在水性电解质中维持MnO阴极的稳定性。由于Ca与SA的强键合作用导致其具有强粘附性、高亲水性和良好的机械稳定性，采用Ca-SA粘结剂的商用微米级MnO阴极在1 C下的容量高于300 mAh/g，大于Mn-SA和Zn-SA（约200 mAh/g）以及PVDF（约150 mAh/g）粘结剂，并且在3 C下250 mAh/g的容量可循环超过200次。这些令人鼓舞的结果可能会释放水性粘结剂在水系电池实际应用中的巨大潜力。
