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Boosting Cell Performance of LiNi 0.8 Co 0.15 Al 0.05 O 2 via Surface Structure Design
Author(s) -
Zheng Junchao,
Yang Zhuo,
Dai Alvin,
Tang Linbo,
Wei Hanxin,
Li Yunjiao,
He Zhenjiang,
Lu Jun
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201904854
Subject(s) - nanopillar , materials science , cathode , hydrofluoric acid , electrolyte , electrochemistry , ion , chemical engineering , rutile , surface modification , electrode , nanotechnology , nanostructure , chemistry , organic chemistry , engineering , metallurgy
Although the high energy density and environmental benignancy of LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) holds promise for use as cathode material in Li‐ion batteries, present low rate capabilities, and fast capacity fade limit its broad commercial applications. Here, it is reported that surface modification of NCA cathode ( R‐3m ) with 5 nm‐thick nanopillar layers and Fm‐3m structures significantly improves electrode structure, morphology, and electrochemical performance. The formation of nanopillar layers increases cycling and working voltage stability of NCA by shielding the host material from hydrofluoric acid and improves structural stability with the electrolyte. The modified NCA cathode exhibits an enhanced 89% capacity retention at a rate of 1 C over that of pristine NCA (75.2%) after 150 cycles and effectively suppresses working voltage fade (a drop of 0.025 V after 300 cycles) during repeated charge–discharge cycles. In addition, the diffusion barrier of Li ions in NCA crystals at 0.80 V is noticeably smaller than that of Li ions in pristine NCA (0.87 eV). These findings demonstrate that this unique surface structure design considerably enhances cycle and rate performance of NCA, which has potential applications in other Ni‐rich layered cathode materials.