多级碳复合的大尺寸硅颗粒在锂离子电池负极中的性能  

Performance of large-scale silicon particles coated with multistage carbon as anode materials for lithium-ion batteries

作　　者：郑瀚 来沛霈 田晓华 孙卓[1] 张哲娟[1] ZHENG Han;LAI Peipei;TIAN Xiaohua;SUN Zhuo;ZHANG Zhejuan(Engineering Research Center for Nanophotonics and Advanced Instrument(Ministry of Education),School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学物理与电子科学学院,纳光电集成与先进装备教育部工程研究中心,上海200241

出　　处：《储能科学与技术》2023年第1期23-34,共12页Energy Storage Science and Technology

基　　金：教育部工程中心主任基金(2021nmc006)。

摘　　要：以光伏电池生产废料中的大尺寸硅颗粒(200~800 nm)为原料,水性聚氨酯(PU)和聚苯胺(PANI)作为碳源,通过液相包裹法和低温热解法制备了不同结构碳复合的硅碳负极材料(SPU与SPU#PANI),分别研究了复合碳含量、微结构与元素掺杂对负极电化学性能的影响。SPU负极中碳复合量低,首次放电比容量高达2193.6 mAh/g,但循环稳定性差。经二级碳复合后的SPU#PANI导电性提高,在多孔碳微结构支撑作用下,不仅获得了较高的放电比容量(1488.8 mAh/g),而且经100次循环后SPU#PANI放电比容量保持在756.8 mAh/g以上,表现出良好的倍率性能。研究结果表明,大尺寸硅颗粒表面复合了具备多孔结构的碳后,不仅为硅充放电过程中的膨胀提供了缓冲,也为锂离子传输提供通道,有效地提升了硅基负极的电化学性能和稳定性。本工作采用的多级碳低温热解复合方法,可为锂离子电池硅基负极产业化技术发展提供重要的借鉴。Silicon-carbon composite materials within various carbon structures(SPU and SPU#PANI) were created using liquid phase wrapping and low-temperature pyrolysis, with large-size silicon particles(200—800 nm) from photovoltaic cell production waste as raw materials and water-based polyurethane(PU) and polyaniline(PANI) as carbon sources. The effects of carbon content, microstructure, and elemental doping on the electrochemical characteristics of SPU and SPU#PANI as anode materials for lithium-ion batteries were investigated. A low content of carbon composite in the SPU results in a high initial discharge capacity of up to 2193.6 mAh/g but poor charge and discharge cycle stability. However, the conductivity of SPU#PANI was increased after a secondary carbon composited. Additionally, it obtains a high discharge capacity(1488.8 mAh/g) as a result of the influence of porous carbon microstructure. The SPU#PANI’s specific capacity was still over 756.8 mAh/g after 100 cycles,indicating good rate performance. The findings showed that the carbon with porous structure composite on the surface of large-size silicon particles serves not only a buffer for the expansion of the silicon in the process of charge and discharge but also a channel for lithiumion transmission, significantly enhancing the electrochemical performance and stability of the silicon-based anode. The low-temperature pyrolysis technique used to composite multistage carbon on large-scale silicon particles provides a key reference for the industrialization technology development of silicon-based anode for lithium-ion batteries.

关 键 词：水性聚氨酯 聚苯胺 多级碳复合 负极 锂离子电池 

分 类 号：O646[理学—物理化学]