硅铁合金/碳跨尺度复配策略及稳定性研究  

Cross-scale composite strategy and stability of silicon iron alloy/carbon

作　　者：龙家英 赵刘洋 黄子岸 唐宏福 吴爱民[1] 宋财根 LONG Jiaying;ZHAO Liuyang;HUANG Zi’an;TANG Hongfu;WUAimin;SONG Caigen(Key Laboratory of Energy Materials and Devices,School of Materials Science and Engineering,Dalian University of Technology,Dalian Liaoning 116024,China;School of Materials Science and Engineering,Dalian Jiaotong University,Dalian Liaoning 116024,China;Ningbo Guangxin Nano Materials Co.,Ltd.,Ningbo Zhejiang 315000,China)

机构地区：[1]大连理工大学材料科学与工程学院辽宁省能源材料及器件重点实验室,辽宁大连116024 [2]大连交通大学材料科学与工程学院,辽宁大连116024 [3]宁波广新纳米材料有限公司,浙江宁波315000

出　　处：《电源技术》2024年第12期2380-2387,共8页Chinese Journal of Power Sources

摘　　要：针对硅材料在充放电过程中产生巨大的体积膨胀导致其循环性能差的瓶颈问题,利用等离子体法制备的纳米硅铁合金与微米石墨球磨复合,再以酚醛树脂热解的无定形碳作为碳包覆层,采用液相包覆-高温热解法实现硅铁合金/碳跨尺度微纳复合结构的设计。实验结果表明,添加一定量的酚醛树脂,有助于增加硅铁合金纳米颗粒与微米石墨之间的界面结合,并将硅铁合金纳米颗粒锚定在微米石墨表面,减轻硅铁合金在充放电过程中的巨大体积膨胀。制备的Si-Fe/G@C负极材料具有优异的导电性、电化学循环稳定性和可逆储锂容量,首次库仑效率为84.16%,在0.05 C下,首次放电比容量可达913.80 mAh/g,0.3 C循环200次后,可逆比容量为611.90 mAh/g,容量保持率为98.95%,在锂离子电池充放电过程中表现出高的循环稳定性。This study addressed the challenge of significant volume expansion during the chargedischarge cycling of silicon materials,which detrimentally impacts their overall cycling performance.Nano-sized silicon-iron alloy was fabricated using a plasma evaporation method,and micron-sized graphite was composite through high-energy ball milling.The amorphous carbon resulting from the pyrolysis of phenolic resin served as the carbon coating layer.The synthesis involved a liquid phase coating-high temperature pyrolysis method aiming at designing Si-Fe alloy/carbon cross-scale nanocomposite structures.The experimental findings indicate that the addition of a certain amount of phenolic resin helps to enhance the interfacial bonding between Si-Fe alloy nanoparticles and micronized graphite,anchoring the Si-Fe alloy nanoparticles to the micronized graphite surface and mitigating the substantial volume expansion of the Si-Fe alloy during the charging and discharging process.The preparation of Si-Fe/G@C anode material exhibits excellent electrical conductivity,superior electrochemical stability,and reversible lithium storage capacity.The initial coulombic efficiency is 84.16%at 0.05 C,the initial discharge specific capacity reaches 913.80 mAh/g,and the reversible specific capacity is 611.9 mAh/g with a capacity retention of 98.95%after 200 cycles at 0.3 C.This results in high cycling stability during the lithiation process in lithium-ion batteries.

关 键 词：锂离子电池 负极材料 硅铁合金 酚醛树脂 跨尺度复配 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]