摘要
Multielectronic reaction electrode materials for high energy density lithium-ion batteries(LIBs)are severely hindered by their inherent sluggish kinetics and large volume variations,leading to rapid capacity fade.Here,a simple method is developed to construct low-carbon and nanosheathed ZnCo_(2)O_(4) porous spheroids(ZCO@C-5).In this micro/nanostructure,an ultrathin amorphous carbon layer(∼2 nm in thickness)is distributed all over the primary nanosized ZCO particles(∼20 nm in diameter),which fnally self-assembles into porous core(ZCO)-shell(carbon)micron spheroids.Te nanoencapsulation and macro/mesoporous architecture can not only provide facile electrolyte penetration and rapid ion/electron transfer but also better alleviate volumetric expansion efect to avoid pulverization of ZCO@C-5 spheroids during repeat charge/discharge processes.As expected,the three-dimensional porous ZCO@C-5 composites exhibit high reversible capacity of 1240 mAh g^(−1) cycle at 500 mA g^(−1),as well as excellent long-term cycling stability and rate capability.Te low-carbon and nanoencapsulation strategy in this study is simple and efective,exhibiting great potential for high-performance LIBs.
基金
This work was fnancially supported by the National Natural Science Foundation of China(21506260,51573215,and U1601211)
Natural Science Foundation of Guangdong Province(2016A030313354 and 2015A030310355)
Guangzhou Scientifc and Technological Planning Project(201607010042,201707010424,and 201804020025)
Guangdong Province Sci&Tech Bureau(2016A050503001,2016B010114004,and 2017B090901003)
Fundamental Research Funds for the Central Universities(18lgpy32,and 171gjc37)
Special Project on the Integration of Industry,Education and Research of Guangdong Province(2015B09090100).
