上海大学学报(自然科学版) ›› 2023, Vol. 29 ›› Issue (5): 973-990.doi: 10.12066/j.issn.1007-2861.2510

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掺杂锰氧化物的聚乙烯醇基碳包覆复合材料的制备及界面改良优化机制 

王雪琪, 喻嘉, 施思齐   

  1. 上海大学 材料科学与工程学院, 上海 200444
  • 收稿日期:2023-05-08 出版日期:2023-10-28 发布日期:2023-11-03
  • 通讯作者: 施思齐 (1978—), 男, 教授, 博士生导师, 博士, 研究方向为基于电化学的能量存储材料的计算材料学等. E-mail:sqshi@shu.edu.cn
  • 基金资助:
    国家自然科学基金联合基金资助项目 (U2030206) 

Preparation and interface improvement mechanism of MnOx-doped PVA-based carbon-coated CFx
composite materials 

WANG Xueqi, YU Jia, SHI Siqi   

  1. School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
  • Received:2023-05-08 Online:2023-10-28 Published:2023-11-03

摘要: 采用掺杂锰氧化物 MnOx 的聚乙烯醇 (polyvinyl alcohol, PVA) 基碳包覆 (CF0.79@CMnOx) 对氟化碳 (CF0.79) 进行改性. 为提升锂氟化碳电池倍率性能, 进一步探讨碳化温度、氧化温度和包覆层厚度对制备的 CF0.79@C-MnOx 复合材料电化学性能的影响, 以此优化氟化碳包覆层获得界面改良最佳优化机制. 实验结果表明: 优化碳化温度, 可得到导电性最好的碳层; 优化氧化温度, 可得到结晶性好的锰氧化物; 优化 PVA 和 Mn(NO3)2 浓度来调控包覆层厚度, 可进一步改善氟化碳的界面, 促进锂离子扩散到氟化碳电极上. 微观形貌表征及电化学性能分析均表明, CF0.79@C-MnOx-350 ◦C 氩气-400 ◦C 氧气-0.25 mol/L Mn(NO3)2-0.25 mol/L PVA 具有最佳的性能, 在高的放电倍率下, 无论在倍率性能还是电压平台, 都优于原始氟化碳和其他掺杂 MnOx 的 PVA 碳包覆复合材料. 

关键词: 氟化碳基锂电池, 锰氧化物, 聚乙烯醇基, 碳化温度, 氧化温度, 包覆层厚度 

Abstract:  MnOx-doped polyvinyl alcohol (PVA)-based carbon-coated CFx was used to modify the fluorinated carbon. We investigated the appropriate carbonisation and oxidation temperatures and the thickness of the MnOx-doped PVA-based carbon coating layer to improve the discharge rate performance of lithium-fluorinated carbon batteries and optimise the fluorinated carbon coating layer. The experimental results show that a highly conductive carbon layer is obtained by the optimised carbonization temperature, and pure crystallised manganese oxide is obtained by optimising the oxidation temperature. The coating thickness is adjusted by optimising the concentrations of PVA and Mn(NO3)2 to improve the fluorocarbon interface and promote the diffusion of lithium ions to the fluorocarbon electrode. Based on the micromorphology characterisation and electrochemical performance analysis of different combinations, CF0.79@C-MnOx-350 ◦C argon-400 ◦C oxygen-0.25 mol/L Mn(NO3)2-0.25 mol/L PVA exhibits the best electrochemical performance with a high discharge rate. Both its discharge rate performance and voltage platform are superior to the original fluorinated carbon and other MnOx-doped PVA-based carboncoated fluorinated carbon materials with other combination mechanisms. 

Key words: lithium-?uorine carbon battery, MnOx, polyvinyl alcohol (PVA), carbonisation temperature, oxidation temperature, coating layer thickness 

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