锌离子电池正极纳米片材料制备和电化学性能研究
2015-10-21陈彦伊徐成俊史珊
陈彦伊 徐成俊 史珊



摘 要:锌离子电池是一种环保、廉价、安全的新型电池,它的电化学行为是正极二氧化锰通过锰的价态转换来存储二价锌离子。二氧化锰作为锌离子电池的正极材料,由于其比表面积大、导电性差等特点导致其容量并不能充分发挥。采用自反应反胶束法制备的二维超薄二氧化锰(MnO2)纳米片作为一种储存锌离子的材料,从整体上提高锌离子电池的容量。以二维超薄二氧化锰(MnO2)纳米片为正极的锌离子电池,当电流密度为0.1 A/g时,最高容量达到484.2 mA·h/g,接近锌离子电池的最大理论容量616 mA·h/g;当电流密度为5 A/g时,电池循环两百圈后的容量保持率也有80%,表现了很好的循环性能。
关 键 词:锌离子电池;二维超薄二氧化锰纳米片
中图分类号:TM 311 文献标识码: A 文章编号: 1671-0460(2015)06-1197-03
Manganese Dioxides Nanosheets/Graphene as the Zinc-ion
Intercalating Materials for High Capacity Zinc Ion Battery
CHEN Yan-yi1,XV Chen-jun2,SHI Shan3
(1. Graduate School at Shenzhen, Tsinghua University, Guangdong Shenzhen 518055, China;
2. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China)
Abstract: Zinc ion battery is a new battery which is environment friendly, inexpensive and safety; its energy storage mechanism is to store divalent zinc ions in manganese dioxide tunnel by conversion of tetravalent manganese to trivalent manganese. Manganese dioxide is as active material to provide the energy for the cell. However, due to its large surface area and poor conductivity characteristics, the theoretical capacity cannot be fully realized. Therefore, we utilize ultrathin two-dimensional nanosheets manganese dioxide (MnO2) as a new zinc-ion intercalating material produced by a self-reacting microemulsion method to improve the capacity of the zinc ion battery. At a current density of 0.1 A/g, the maximum capacity is 484.2 mA?h/g, which is very close to the theoretical capacity of the zinc-ion battery. At the current density of 5 A/g, the capacity retention rate is still 80% after two hundred cycles, which shows good cycle performance.
Key words: Zinc ions battery; Ultrathin two-dimensional manganese dioxide nanosheets
環境是人类生存和发展的基础,随着环境污染,全球气候变暖,煤、石油等不可再生能源不断消耗,人类社会对于开发新型能源的要求越来越迫切。随着信息化时代的到来,储能器件在当今社会中越来越多的起到了主导作用。
近几年来锌离子电池的发明,满足了人们对于一个理想储能器件的想象—高容量(锌离子电池理论容量在308和616 mA·h/g之间)、快速充放电、安全、环境友好、成本低,因此,锌离子电池可以广泛的运用于消费电子、电动车、运输工具,甚至军事用途等。锌离子电池是由以二氧化锰(MnO2)为正极,金属锌为负极,含有锌离子Zn2+的中性水溶液为电解液所组成。锌离子电池的发明是基于以下两种电化学行为:(1)在含有Zn2+的的中性水溶液,Zn2+可以快速可逆的在金属锌箔的表面沉积和溶解; (2)在相同的溶液中,Zn2+可以可逆的在MnO2隧道中嵌入或脱出[1]。……
