Activating lithium storage in 2D CaSi_(2) anode via enhancing pseudocapacitive properties with oxygen modification engineering  

作　　者：Yongzheng Zhang Lu Sun Kailin Yang Youwang Ye Liang Zhan Qi Wei Jianan Gu 

机构地区：[1]Institute of Energy Power Innovation,North China Electric Power University,Beijing 100096,China [2]State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China [3]State Key Laboratory of Mesoscience and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China [4]Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering,AVIC Manufacturing Technology Institute,Beijing 100024,China

出　　处：《Nano Research》2025年第4期199-206,共8页纳米研究(英文版)

基　　金：supported partially by project of the National Natural Science Foundation of China(Nos.62474064 and 52102203);the Fundamental Research Funds for the Central Universities(No.2024MS082);the NCEPU“Double First-Class”Program.

摘　　要：Silicon(Si)has emerged as a promising anode material for lithium-ion batteries(LIBs)due to its extremely high theoretical capacity of 4200 mAh·g^(-1).However,its practical application is limited by several critical challenges,including severe volume expansion and poor electrical conductivity.Herein,we employ a two-dimensional(2D)oxygen modification engineering approach to fabricate 2D oxygen-functionalized CaSi_(2)(CaSi_(2)O_(x))layers.During the preparation of 2D CaSi_(2) layers,O atoms are gradually incorporated onto their surface.The resulting 2D CaSi_(2)O_(x) layers have a thickness of 3-5 nm,closely matching the theoretical thickness of 6-10 layers.When used as lithium anodes,the 2D CaSi_(2)O_(x) layers exhibit exceptional electrochemical performance,maintaining stability over 3000 cycles at an ultrahigh current density of 30 A·g^(-1).By tailoring the surface properties,their pseudocapacitive charge storage mechanism is significantly enhanced,effectively overcoming the intrinsic limitations of traditional Si anodes.This study highlights the promise of 2D surface engineering in the development of advanced materials for next-generation LIBs.

关 键 词：two-dimensional(2D)CaSi_(2)O_(x) Si anode volume change PSEUDOCAPACITIVE surface modification lithium storage 

分 类 号：O646[理学—物理化学] TM912[理学—化学]