American Chemical Society
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Rational Design of Multifunctional Surface Modification for Ni-Rich Layered Cathodes of Lithium-Ion Batteries

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journal contribution
posted on 2023-12-05, 18:03 authored by Ha Neul Kim, Taeeun Yim
Although Ni-rich layered oxide materials (LNCMs) have received increasing attention as advanced cathode materials, their short lifespan constitutes a major limitation. In this work, we incorporate Ti- and B-functionalized cathode–electrolyte interphase (CEI) layers at the interface of LNCM cathodes via a simple one-step thermal process with boric acid (H3BO3) and titanium dioxide (TiO2). It is discovered that coating TiO2 increases the mechanical strength of LNCM cathode materials, effectively suppressing the microcracking of LNCM cathode particles. Furthermore, H3BO3 can react with residual lithium remaining at the LNCM cathode surface, which also leads to a decrease in the internal pressure of the cell and a minimization of reduction of ionic conductivity as CEI layers are formed at the LNCM interfaces. The incorporation of Ti- and B-functionalized CEI layers exhibits a synergistic effect, preventing undesired reactions and improving the surface stability of the LNCM cathodes. In the lifespan, the 0.75 wt % Ti- and B-functionalized LNCM cathode exhibits a 21.9%p increase in retention compared to LNCM cathodes after 100 cycles, even at high temperature. Postmodern analyses of cycled LNCM cathodes, including (cross-sectional) SEM, EIS, XPS, and ICP-MS, demonstrate that bifunctionalized LNCM cathodes reveal improved particle strength and markable suppression of electrolyte decomposition.