水系锌离子电池由于其低成本、高丰度和高理论比容量等优势,在后锂电时代的新型储能体系中脱颖而出,受到学界的广泛关注。开发稳定高效的储锌正极材料,是锌离子电池发展的重点和难点。多金属氧酸盐(简称多酸),具有较强的氧化还原活性和多电子转移特性,被视为极具潜力的电极材料,但多酸易溶解、易团聚和导电性较差等问题,阻碍了其在储能领域的应用。为解决上述问题,采用氧化石墨烯(GO)为基底材料,在其表面原位生长聚苯胺(PANI),通过静电相互作用固载Keggin型多酸H3PMo12O40,得到了rGO-PANI-PMo12(GPM)复合材料,利用石墨烯及其表面功能基团,提高多酸的抗流失性、分散性和导电性。通过XRD、FTIR、SEM、TEM、XPS以及电化学性能测试等方法,探究了GO和苯胺单体(ANI)的比例对GPM材料的形貌、结构和电化学性能的影响规律。结果表明:当GO和ANI在质量比为1∶20时,所制备的GPM材料融合多酸和石墨烯的优点,兼具较强的氧化还原活性和高导电性,表现出优异的电化学性能,在0.2A/g下,放电比容量高达258mAh/g,且在2A/g的条件下,循环1000圈容量保持率为82.2%。此外,反应动力学研究结果表明,GPM电极的电化学反应过程为扩散和电容共同控制,表现出较快的Zn2+扩散速率和电荷转移速率。

In recent years,water-zinc ion batteries have been widely concerned in the new energy storage system in the post-lithium eradue to their advantages of low cost,abundant resources,and high theoretical capacity of the zinc negative electrode. However,findingsuitable cathode materials is the key and challenge in the development of zinc-ion batteries. Polyoxomethanate (abbreviated aspolyacids) are considered to be a highly promising electrode material due to their high redox activity and multi-electron transfercharacteristics. However,issues such as easy dissolution,easy agglomeration,and poor conductivity of polyacids have hindered theirapplication in the energy storage field. In order to solve these problems,polyaniline (PANI) was in-situ grown on the surface ofgraphene oxide (GO) as the substrate,and Keggin-type polyacid H3PMo12O40 was supported by electrostatic interaction. Finally,therGO-PANI-PMo12 (GPM) composite materials were prepared. The intention of this work was to utilize graphene and its surface functional groups to improve the immobilization,dispersibility,and conductivity of polyacids. The characterizations of XRD,FTIR,SEM,TEM,XPS,and electrochemical performance tests were used to explore the influence of the ratio of GO and ANI on their morphology,structure,and electrochemical performance. The results showed that when the mass ratio of GO to ANI was 1∶20,the prepared GPMmaterial exhibited both high redox activity of polyacids and high conductivity of graphene,having a high discharge specific capacity of258 mAh/g at 0.2 A/g,and a capacity retention rate of 82.2% after 1000 cycles at 2 A/g,demonstrating good cycle stability. In addition,theresults of reaction kinetics studies indicate that the electrochemical reaction process of the GPM electrode is controlled by both diffusionand capacitance,thus exhibiting a faster Zn diffusion rate and charge transfer rate.