Hou P, Zhang H, Deng X, Xu X, Zhang L. Stabilizing the Electrode/Electrolyte Interface of LiNi
0.8Co
0.15Al
0.05O
2 through Tailoring Aluminum Distribution in Microspheres as Long-Life, High-Rate, and Safe Cathode for Lithium-Ion Batteries.
ACS APPLIED MATERIALS & INTERFACES 2017;
9:29643-29653. [PMID:
28782929 DOI:
10.1021/acsami.7b05986]
[Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The unstable electrode/electrolyte interface of high-capacity LiNi0.8Co0.15Al0.05O2 (NCA) cathodes, especially at a highly delithiated state, usually leads to the transformation of layered to spinel and/or rock-salt phases, resulting in drastic capacity fade and poor thermal stability. Herein, the Al-increased and Ni-,Co-decreased electrode surface is fabricated through tailoring element distribution in micrometer-sized spherical NCA secondary particles via coprecipitation and solid-state reactions, aimed at stabilizing the electrode/electrolyte interface during continuous cycles. As expected, it shows much extended cycle life, 93.6% capacity retention within 100 cycles, compared with that of 78.5% for the normal NCA. It also delivers large reversible capacity of about 140 mAh g-1 even at 20 C, corresponding to energy density of around 480 Wh kg-1, which is enhanced by 45% compared to that of the normal NCA (about 330 Wh kg-1). Besides, the delayed heat emission temperature and reduced heat generation mean remarkably improved thermal stability. These foregoing improvements are ascribed to the Al-increased spherical secondary particle surface that stabilizes the electrode/electrolyte interface by protecting inner components from directly contacting with electrolyte and suppressing the side reaction on electrode surface between high oxidizing Ni4+ and electrolyte.
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