Failure mechanism of LiNi0.6Co0.2Mn0.2O2 cathodes in aqueous/non-aqueous hybrid electrolyte

Du, Leilei1; Hou, Xu2; Berghus, Debbie1; Frankenstein, Lars1; Schmuch, Richard1; Wang, Jun3; Paillard, Elie4; Winter, Martin1,2; Placke, Tobias1; Li, Jie2,4

2023

10.1039/d2ta08650f

Journal of Materials Chemistry A   Impact Factor & Quartile

2050-7488

2050-7496

The urgent need for improving the energy density of aqueous lithium ion batteries (ALIBs) can be addressed by the implementation of advanced electrode materials and electrolytes. The utilization of layered oxide cathodes, particularly Li[NixCoyMnz]O-2 (NCM) materials, is an effective strategy, as they can offer high specific capacities in an appropriate voltage range. However, due to the strong effect of humidity on the degradation of Ni-rich layered oxide cathodes, using these materials together with highly concentrated aqueous electrolytes is critical. In this work, the underlying mechanisms responsible for the degradation of Li[Ni0.6Co0.2Mn0.2]O-2 (NCM622)||TiO2@LiTi2(PO4)(3) (P/N = 1.2 : 1) full-cells are systematically explored by comprehensive studies, involving the evolution of the lattice structure of NCM622 and electrochemical impedance dependent on the operating voltage range (0.7-2.8 V or 0.7-2.9 V). It is found that in aqueous/non-aqueous hybrid electrolyte, in addition to the discharge process, proton intercalation into NCM622 also takes place during the charging process, which is dramatically severe at higher upper cut-off voltage (2.9 V), leading to a rapid degradation of the cathode material. The intercalated protons not only aggravate the electrochemical impedance by blocking Li+ diffusion, but also activate the higher potential redox pairs. This experimental study offers an in-depth understanding about the failure mechanism of NCM622 cathode materials in aqueous electrolytes.

SCI

English

Others

German Research Foundation (DFG)[Li 2916/2-1] ; Ministry of Economic Affairs, Innovation, Digitalization and Energy of the State of North Rhine-Westphalia (MWIDE)[313-W044A] ; European Union[829145]

Chemistry ; Energy & Fuels ; Materials Science

Chemistry, Physical ; Energy & Fuels ; Materials Science, Multidisciplinary

WOS:000922078300001

ROYAL SOC CHEMISTRY

Web of Science

1.Univ Munster, Inst Phys Chem, MEET Battery Res Ctr, Corrensstr 46, D-48149 Munster, Germany
2.Forschungszentrum Julich, Helmholtz Inst Munster HI MS, IEK 12,Corrensstr 46, D-48149 Munster, Germany
3.Southern Univ Sci & Technol, Sch Innovat & Entrepreneurship, Shenzhen 518055, Peoples R China
4.Politecn Milan, Dept Energy, Via Lambruschini 4, I-20156 Milan, Italy

Du, Leilei,Hou, Xu,Berghus, Debbie,et al. Failure mechanism of LiNi0.6Co0.2Mn0.2O2 cathodes in aqueous/non-aqueous hybrid electrolyte[J]. Journal of Materials Chemistry A,2023.

Du, Leilei.,Hou, Xu.,Berghus, Debbie.,Frankenstein, Lars.,Schmuch, Richard.,...&Li, Jie.(2023).Failure mechanism of LiNi0.6Co0.2Mn0.2O2 cathodes in aqueous/non-aqueous hybrid electrolyte.Journal of Materials Chemistry A.

Du, Leilei,et al."Failure mechanism of LiNi0.6Co0.2Mn0.2O2 cathodes in aqueous/non-aqueous hybrid electrolyte".Journal of Materials Chemistry A (2023).