Optimal geometrical configuration and oxidation state of cobalt cations in spinel oxides to promote the performance of Li-O_(2) battery  

作　　者：Yu Zhang Shuting Zhang Mengwei Yuan Yufeng Li Rong Liu Caiyun Nan Chen Chen 

机构地区：[1]Engineering Research Center of Advanced Rare Earth Materials,Department of Chemistry,Tsinghua University,Beijing 100084,China [2]Beijing Key Laboratory of Energy Conversion and Storage Materials Institution,College of Chemistry,Beijing Normal University,Beijing 100875,China [3]X-ray diffraction Lab,Analytical and Testing Center,Beijing Normal University,Beijing 100875,China

出　　处：《Nano Research》2024年第1期221-227,共7页纳米研究（英文版）

基　　金：supported by the National Key R&D Program of China(No.2021YFF0500503);the National Natural Science Foundation of China(Nos.21925202 and U22B2071).

摘　　要：Co_(3)O_(4) is considered as one of promising cathode catalysts for lithium oxygen(Li-O_(2))batteries,which contains both tetrahedral Co^(2+)sites(Co^(2+)Td)and octahedral Co^(3+)sites(Co^(3+)Oh).It is important to reveal the effect of optimal geometric configuration and oxidation state of cobalt ion in Co_(3)O_(4) to improve the performance of Li-O_(2) batteries.Herein,through regulating the synthesis process,Co^(2+)and Co^(3+)sites in Co_(3)O_(4) were replaced with Zn and Al atoms to form materials with a unique Co site.The Li-O_(2) batteries based on ZnCo_(2)O_(4) showed longer cycle life than that of CoAl_(2)O_(4),suggesting that in Co_(3)O_(4),the Co^(3+)Oh site is a relatively better geometric configuration than Co^(2+)Td site for Li-O_(2) batteries.Theoretical calculations revealed that Co^(3+)Oh sites provide higher catalysis activity,regulating the adsorption energy of the intermediate LiO_(2) and accelerating the kinetics of the reaction in batteries,which further leads to the change of the morphology of the discharge product and ultimately improves the electrochemical performance of the batteries.

关 键 词：lithium oxygen(Li-O_(2))batteries geometrical configuration oxidation state lithium peroxide 

分 类 号：O64[理学—物理化学]