面向锌离子电池的二氧化锰柔性电极制备及电化学性能  

Preparation and electrochemical properties of manganese dioxide flexible electrodes for zinc-ion batteries

作　　者：习爽 程溪明 高兴伟 刘辉龙 XI Shuang;CHENG Ximing;GAO Xingwei;LIU Huilong(School of Mechanical and Electronic Engineering,Nanjing Forestry University,Nanjing 210037,China;School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]南京林业大学机械电子工程学院,南京210037 [2]广东工业大学机电工程学院,广州510006

出　　处：《工程科学学报》2024年第11期2036-2045,共10页Chinese Journal of Engineering

基　　金：南京林业大学校青年科技创新基金资助项目(CX2017008);省部共建精密电子制造技术与装备国家重点实验室开放课题资助项目(JMDZ202303)。

摘　　要：二氧化锰(MnO_(2))作为锌离子电池常用的正极材料,在自然界中储量丰富、安全性好、理论容量高,受到研究学者的广泛关注.制备高性能锌离子电池的关键问题之一是构造具有稳定微观结构的阴极.本文选用具有优良导电性的柔性碳布(CC)作为基底,分别使用还原沉积法和电化学沉积法制备了碳布@二氧化锰(CC@MnO_(2))阴极,使用SEM、TEM、XRD、XPS等测试手段对两种工艺条件下得到的电极结构和形貌进行表征分析,探明了电极的微观结构组成.进一步将其组装成扣式锌离子电池,对比研究了不同工艺参数下电池的电化学性能.结果表明,还原沉积法中,使用0.40 mol·L^(-1)KMnO_(4)+0.50 mol·L^(-1)H_(2)SO_(4)的混合溶液制备的电极具备最优的储锌性能(电流密度在0.1 A·g^(-1)时能提供最大为291 m A·h·g^(-1)的放电比容量)、能量密度(293.3 W·h·kg^(-1)和循环稳定性(1 A·g^(-1))电流密度下进行1000次循环后,容量保持率为90.48%,库伦效率为99.87%).此外,通过对电极进行不同充放电状态下的非原位XRD和SEM检测,进一步探索了充放电过程的储能机制.本文深入探讨了基于还原沉积法的CC@MnO_(2)电极优化制备工艺,为高性能锌离子电池的开发提供了重要的参考依据.Manganese dioxide(MnO_(2)),a commonly used cathode material for zinc-ion batteries(ZIBs),has attracted considerable attention owing to its abundant reserves in nature,safety,and high theoretical capacity.One of the key challenges in the preparation of high-performance zinc-ion batteries is the construction of a cathode with a stable microstructure.In this study,a flexible and conductive carbon cloth(CC)was chosen as the substrate onto which manganese dioxide(MnO_(2))was deposited through either reductive deposition or electrochemical deposition methods to form a carbon cloth@manganese dioxide(CC@MnO_(2))cathode.For the reductive deposition method,a precursor solution of KMnO4 and H2SO4 was used,and various concentrations were adopted to synthesize the CC@MnO_(2) cathode.The synthesized electrode is referred to as the CC@MnO_(2)-reductive deposition cathode.Specifically,KMnO4 solutions with concentrations of 0.25,0.40,and 0.55 mol·L^(−1) were mixed with H2SO4 at concentrations of 0.20 mol·L^(−1) and 0.50 mol·L^(−1).For the electrochemical deposition method,MnO_(2) nanoparticles were decorated on CC using a three-electrode system under the potentiostatic mode at a potential of 1.1 V for 1500 s.A depositing electrolyte consisting of 0.1 mol·L^(−1) MnSO4+0.1 mol·L^(−1) Na2SO4 was used.The synthesized electrode is referred to as the CC@MnO_(2)-electrochemical deposition cathode.The cathodes synthesized under different parameters were comparatively analyzed via scanning electron microscopy,transmission electron microscopy,X-ray diffraction,and X-ray photoelectron microscopy to explore their morphology and microstructure.Furthermore,the prepared CC@MnO_(2) cathodes were assembled into button-type zinc-ion batteries,and their electrochemical properties,charging/discharging performance,and cycling stability were evaluated.The test results showed that the Zn//CC@MnO_(2) cells based on the reductive deposition method with a 0.40 mol·L^(−1) KMnO4+0.50 mol·L^(−1) H2SO4 mixed solution delivered optimal zin

关 键 词：锌离子电池 二氧化锰 电化学沉积 还原沉积 储锌性能 

分 类 号：O646[理学—物理化学]