한국표면공학회지 (56권1호 104-114)
Three-dimensional porous films consisting of copper@cobalt oxide coreshell dendrites for high-capacity lithium secondary batteries
리튬이차전지용 고용량 음극을 위한 구리@코발트산화물 코어-쉘 수지상 기반 3차원 다공성 박막
주소영a, 최윤주a,b, 최우성a,*, 신헌철a,*
So-Young Jooa, Yunju Choia,b, Woo-Sung Choia,* and Heon-Cheol Shina,*
a부산대학교 재료공학과, b한국기초과학지원원구원 부산센터
aSchool of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea bKorea Basic Science Institute, Busan Center, Busan 46742, Republic of Korea
Three dimensional (3D) porous structures consisting of Cu@CoO core-shell-type nano-dendrites were synthesized and tested as the anode materials in lithium secondary batteries. For this purpose, first, the 3D porous films comprising Cu@Co core-shell-type nano-dendrites with various thicknesses were fabricated through the electrochemical co-deposition of Cu and Co. Then the Co shells were selectively anodized to form Co hydroxides, which was finally dehydrated to get Cu@CoO nano-dendrites. The resulting electrodes exhibited very high reversible specific capacity almost 1.4~2.4 times the theoretical capacity of commercial graphite, and excellent capacity retention (~90%@50th cycle) as compared with those of the existing transition metal oxides. From the analysis of the cumulative irreversible capacity and morphology change during charge/discharge cycling, it proved that the excellent capacity retention was attributed to the unique structural feature of our core-shell structure where only the thin CoO shell participates in the lithium storage. In addition, our electrodes showed a superb rate performance (70.5%@10.8 C-rate), most likely due to the open porous structure of 3D films, large surface area thanks to the dendritic structure, and fast electron transport through Cu core network.
Cobalt oxide; Core-shell; Dendrite; Anode; Lithium battery.
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