Enhanced mechanical strength and electrochemical performance of core–shell structured high–nickel cathode material

Journal Article · Thu Nov 07 23:00:00 EST 2019 · Journal of Power Sources

DOI:https://doi.org/10.1016/j.jpowsour.2019.227395· OSTI ID:1606409

Maeng, Sangjin ^[1]; Chung, Youngmin ^[2]; Min, Sangkee ^[1]; Shin, Youngho ^[2]

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1. Univ. of Wisconsin, Madison, WI (United States)
2. Argonne National Lab. (ANL), Lemont, IL (United States)

Improving capacity retention during cycling and the thermal–abuse tolerance of layered high–nickel cathode material, LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811), is a significant challenge. In this work, a series of core–shell structured cathode materials with the overall composition of LiNi_0.8Mn_0.1Co_0.1O₂ was prepared via a coprecipitation method in which the nickel–rich composition (LiNi_0.9Mn_0.05Co_0.05O₂) is the core and the manganese–rich composition (LiNi_0.33Mn_0.33Co_0.33O₂) is the shell. In terms of achieving a higher nickel content (more than 80%) of heterogeneous material, this core–shell structured material is a more practical approach because it has a larger nickel–rich core region and a thicker manganese–rich shell than the full–concentration gradient material, not to mention being more feasible for continuous mass production. Analysis of mechanical strength through nanoindentation shows that the core–shell structured NMC811 has higher stiffness and compressive stress–strain than the commercial homogeneous NMC811 and retains the mechanical strength and the binding force strong enough to prevent crack formation even after 200 cycles. The prepared core–shell structure NMC811 exhibits a greatly improved capacity retention of 76.6% compared to the commercial homogeneous NMC811 with a capacity retention of 39.6% after 200 cycles. This material also exhibits significantly improved thermal stability over the commercial homogeneous NMC811.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V); USDOE Office of Science (SC)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1606409
• Alternate ID(s): OSTI ID: 1592525
• Journal Information: Journal of Power Sources, Journal Name: Journal of Power Sources Journal Issue: C Vol. 448; ISSN 0378-7753
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
cathode
core-shell
high-nickel
lithium-ion batteries
mechanical failure
stress-strain curve