SnTe nanoparticles physicochemically encapsulated by double carbon as conversion-alloying anode materials for superior potassium-ion batteries  

作　　者：Ting Li Yikun Wang Qianwen Zhou Lingling Yuan Shuangyan Qiao Meng Ma Zhengqing Liu Shaokun Chong 

机构地区：[1]Frontiers Science Center for Flexible Electronics(FSCFE),Xi’an Institute of Flexible Electronics(IFE)and Xi’an Institute of Biomedical Materials&Engineering,Northwestern Polytechnical University,Xi’an 710072,China [2]Research&Development Institute of Northwestern Polytechnical University in Shenzhen,Shenzhen 518063,China

出　　处：《Journal of Materials Science & Technology》2023年第27期86-95,共10页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(No.52207248);China Postdoctoral Science Foun-dation(Nos.2022M722606,2021TQ0266);Natural Science Basic Research Program of Shaanxi(No.2022JQ-113);Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110164 and 2022A1515010208);the Fundamental Research Funds for the Central Universities(No.G2020KY0534)。

摘　　要：Telluride tin(SnTe)is a promising conversion-alloying anode for potassium-ion batteries(PIBs)due to its high theoretical specific capacity induced by multi-electron transport reaction and low operating voltage,whereas huge volume expansion and poor kinetics behavior become key scientific bottleneck limiting the battery performances.Herein,SnTe nanoparticles physicochemically wrapped by graphene and nitrogen-doped carbon(SnTe@rGO@NC)are proposed as anode materials for PIBs.The pre-electrostatic interaction urges the formation of Sn-C and Te-C chemical bonds between SnTe and double carbon to strengthen the interfacial stability and electron transfer,and the conductive architecture with hierarchical encapsulation effect is beneficial to maintaining the electrode integrity and electrochemical dynamics.It is demon-strated from first principles calculations and experimental results that SnTe@rGO@NC contributes fast electron transmission,strong K-ion adsorption,and superior K-ion diffusion capability.Ex-situ characteri-zations uncover that SnTe undergoes conversion-alloying dual-mechanism with the products of K_(2)Te and K_(4)Sn_(23)replied on Sn redox site(23SnTe+50K^(+)+50e^(-)↔K_(4)Sn_(23)+23K_(2)Te).Thus,the SnTe@rGO@NC electrode delivers a high initial charge specific capacity of 243.9 mAh g^(-1)at 50 mA g^(-1),superior rate performance(112.6 mAh g^(-1)at 1.0 A g^(-1)),and outstanding cyclic stability at various current densities.

关 键 词：Potassium-ion batteries Anode materials Tin telluride Chemical bonding Conversion-alloying mechanism 

分 类 号：TM912[电气工程—电力电子与电力传动] TB332[一般工业技术—材料科学与工程]