Zhang Feng, Ma Jinjin, Song Hao, He Luying, Zhang Jingwei, Wang Enwei
School of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian 463000, China; National & Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials, Henan University, Kaifeng 475004, China; Haohua Junhua Group Co. LTD, China.
School of Chemistry and Pharmaceutical Engineering, Huanghuai University, Zhumadian 463000, China.
J Colloid Interface Sci. 2023 Dec 15;652(Pt A):104-112. doi: 10.1016/j.jcis.2023.08.074. Epub 2023 Aug 12.
Aqueous nickel-zinc (Ni-Zn) batteries have received increasing research interests because of their reliable safety and economical-friendliness. However, the retarded ionic diffusion, low capacity and limited stability of traditional Ni-based cathodes greatly impedes the practical application of Ni-Zn batteries. Herein, two metal organophosphonate materials of Ni methylphosphonate (Ni-MPA) and Ni phenylphosphonate (Ni-PPA) directly grown on Ni foam are constructed successfully through one step solvothermal technique. These two self-supported Ni organophosphonates featured hybrid two-dimensional (2D) structures consisting of alternating inorganic and organic layers, where the inorganic layers are formed by six-coordinated Ni bridged by oxygen atoms and capped by organophosphonate groups, availing to provide rich open redox reaction sites, rapid ion diffusion and structural flexibility. The research results reveal that the organic groups in phosphonic acid ligands have important influence on their electrochemical properties. Consequently, the Ni-MPA electrode exhibits a higher specific capacity of 2.27 mAh/cm compared to that of the Ni-PPA electrode (1.1 mAh/cm) at 3.0 mA/cm; however, it demonstrates a more rapid transformation rate into Ni(OH) in an alkaline solution. Furthermore, the constructed Ni-MPA//Zn battery can deliver an impressive areal energy density of 2.95 mWh/cm, good rate performance as well as a long-term cycling stability.
水系镍锌（Ni-Zn）电池因其可靠的安全性和经济性而受到越来越多的研究关注。然而，传统镍基阴极的离子扩散受阻、容量低和稳定性有限，极大地阻碍了镍锌电池的实际应用。在此，通过一步溶剂热技术成功构建了两种直接生长在泡沫镍上的金属有机膦酸盐材料，即甲基膦酸镍（Ni-MPA）和苯基膦酸镍（Ni-PPA）。这两种自支撑的镍有机膦酸盐具有由交替的无机和有机层组成的混合二维（2D）结构，其中无机层由通过氧原子桥连并由有机膦酸酯基团封端的六配位镍形成，有利于提供丰富的开放氧化还原反应位点、快速的离子扩散和结构灵活性。研究结果表明，膦酸配体中的有机基团对其电化学性能有重要影响。因此，在3.0 mA/cm的电流密度下，Ni-MPA电极的比容量为2.27 mAh/cm²，高于Ni-PPA电极（1.1 mAh/cm²）；然而，它在碱性溶液中向Ni(OH)的转变速率更快。此外，所构建的Ni-MPA//Zn电池可提供令人印象深刻的面积能量密度2.95 mWh/cm²、良好的倍率性能以及长期循环稳定性。
