高等学校化学学报 ›› 2021, Vol. 42 ›› Issue (6): 1816.doi: 10.7503/cjcu20200896

• 物理化学 • 上一篇    下一篇

三维多孔MnOx@In2O3立方盒子的构筑及储锌性能

樊小勇(), 毋妍, 孙瑞波, 苟蕾, 李东林()   

  1. 长安大学材料科学与工程学院, 西安 710061
  • 收稿日期:2020-12-26 出版日期:2021-06-10 发布日期:2021-06-08
  • 通讯作者: 樊小勇,李东林 E-mail:xyfan@chd.edu.cn;dlli@chd.edu.cn
  • 基金资助:
    陕西省国际合作项目(2020KW-024)

Construction and Zn Storage Performance of Three Dimensional Porous MnOx@In2O3 Cubes

FAN Xiaoyong(), WU Yan, SUN Ruibo, GOU Lei, LI Donglin()   

  1. School of Materials Science and Engineering,Chang’an University,Xi’an 710061,China
  • Received:2020-12-26 Online:2021-06-10 Published:2021-06-08
  • Contact: FAN Xiaoyong,LI Donglin E-mail:xyfan@chd.edu.cn;dlli@chd.edu.cn
  • Supported by:
    the International Scientific and Technological Cooperation Projects of Shaanxi Province, China(2020KW?024)

摘要:

锰基氧化物作为锌离子电池正极具有高比容量和低成本等优点, 但在电化学循环过程中不可逆相变、 锰的溶解和电极/电解质界面不稳定导致其在小电流密度、 深度放电条件下的循环性能差. 针对以上问题, 合成了三维(3D)多孔MnOx立方盒子, 并在其表面包覆In2O3层, 获得3D多孔MnOx@In2O3立方盒子. 结果显示, MnOx@In2O3立方盒子具有大量孔径约10 nm左右的孔, 有利于H+和Zn2+的快速传输; In2O3包覆层均匀包覆于3D多孔MnOx立方盒子的孔壁上, 有利于抑制MnOx在电化学循环过程中的不可逆相变和锰的溶解, 稳定电极/电解质界面. 电化学测试结果表明, 该3D多孔MnOx@In2O3电极在0.3 A/g的小电流密度、 深度放电条件下能稳定循环400次以上, 容量保持260 mA·h/g; 在1. 8 A/g电流密度下可稳定循环4000次以上, 容量保持81 mA·h/g; 即使在高电流密度6.0 A/g下仍保持73.4 mA·h/g的高可逆容量. 恒电流间隙滴定(GITT)和循环伏安测试结果表明, 3D多孔MnOx@In2O3电极比3D多孔MnOx具有更高的离子扩散速率, 有利于提升其高倍率容量. 电化学阻抗谱结果表明, 3D多孔MnOx@In2O3电极具有比3D多孔MnOx更稳定的电极/电解质界面, 有利于提升其循环寿命. 2000次循环后的扫描电子显微镜(SEM)结果表明, MnOx@In2O3电极表面仍分布少量In2O3, 以确保电极/电解质界面和循环的稳定性.

关键词: 锌离子电池, 正极, 锰基氧化物, 三维多孔, 三氧化二铟包覆

Abstract:

Mn-based oxides have been widely researched as the cathode of Zn-ion batteries due to their high capacity and low-cost. However, their phase transformation, dissolution of Mn and unstable electrode/electrolyte interphase during cycling cause poor cycle lifespan, especially poor lifespan at low current densities and high discharge depth. In this work, three-dimensional(3D) porous MnOx cubes were prepared and then a In2O3 layer was coated on their surface to gain 3D porous MnOx@In2O3 cubes. The rich pores with size about 10 nm are beneficial to the rapid transport of H+ and Zn2+, In2O3 coating layer is beneficial to suppressing the dissolution of Mn and phase transformation of MnOx electrodes and stabilize the electrode/electrolyte interphase during cycling. The 3D porous MnOx@In2O3 electrodes deliver high capacity of 260 mA·h/g after 400 stable cycles at a small current density of 0.3 A/g, which is much better than most of reports. Besides, it also delivers high capacity of 81 mA·h/g after 4000 stable cycles at 1.8 A/g, high capacity of 73.4 mA·h/g even at high current density of 6.0 A/g. The Galvanostatic intermittent titration technique(GITT) and CV results reveal 3D porous MnOx@In2O3 electrode has lower electrochemical polarization and large diffusion coefficient than those of 3D porous MnOx electrode. The electrochemical impedance spectra results demonstrate 3D porous MnOx@In2O3 electrode has more stable electrode/electrolyte interphase than that of 3D porous MnOx electrode. The SEM images of 3D porous MnOx@In2O3 electrode suffered 2000 cycles show a little In2O3 still dispersing on the MnOx surface, which ensures the structure stability and stable cyclability.

Key words: Zn-ion battery, Cathode, Mn-based oxide, Three dimensional porous, In2O3 Coating layer

中图分类号: 

TrendMD: