Constructing globally consecutive 3D conductive network using P-doped biochar cotton fiber for superior performance of silicon-based anodes  

作　　者：Jun Cao Jianhong Gao Kun Wang Zhuoying Wu Xinxin Zhu Han Li Min Ling Chengdu Liang Jun Chen 

机构地区：[1]Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology,College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China [2]Institute of Zhejiang University-Quzhou,Zheda Road 99,Quzhou 324000,China

出　　处：《Journal of Materials Science & Technology》2024年第6期181-191,共11页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.12205252);the Basic Public Welfare Re-search Special Project of Zhejiang Province(No.LZY22B040001);the Quzhou Science and Technology Plan Project(No.2022K39);Science and Technology Project of Quzhou Research Institute,Zhejiang University(Nos.IZQ2021KJ2032,IZQ2022KJ3014,and IZQ2022KJ3002);Independent scientific Research Project of Quzhou Research Institute,Zhejiang University(No.IZQ2021RCZX007);New“115 talents”Project ofQuzhou,National Nature Science Foundation of China(No.52172244);Fundamental Research Funds for the Central University(No.226202200053).

摘　　要：The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries(LIBs).The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges,however,the exorbitant costs and the uncertainty of the conductive structure persist,leaving ample room for improvement.Herein,silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network.The network serves a dual purpose:enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity.The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350℃.Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents,the consecutive network can affirm the improvement of the conductivity at a macro level.Moreover,first-principle calculations further validated that the rapid diffusion of Li^(+)is attributed to the tailored electronic microstructure and charge rearrangement of the fiber.The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance(capacity retention of 1777.15 mAh g^(-1) vs.682.56 mAh g^(-1) after 150 cycles at 0.3 C)and rate performance(1244.24 mAh g^(-1) vs.370.28 mAh g^(-1) at 2.0 C).The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes,thereby enabling the fabrication of high-performance LIBs.

关 键 词：3D conductive network Biochar carbon-silicon anode Heteroatoms doping strategy DFT calculation Lithium-ion battery 

分 类 号：TM273[一般工业技术—材料科学与工程]