Towards the high-energy-density battery with broader temperature adaptability: Self-discharge mitigation of quaternary nickel-rich cathode

The application range of nickel-rich layered oxide cathodes is seriously hampered by the structural collapse, cycling decay and self-discharge issues under extreme temperature conditions. In this study, the real-time phase evolution of the LiNi_0.8Mn_0.1Co_0.1O₂ (NMC-811) cathode is investigated at the idling charged state and upon the high temperature galvanostatic cycling. Correspondingly, a quaternary system, consisting of LiNi_0.79Mn_0.1Co_0.1Al_0.01O₂ (NMCA), with the primary particles encapsulated by the glassy LiBO₂ network is proposed; the multiscale strategy collectively suppresses the performance deterioration at the static and dynamic processes, such as the unfavorable phasic transition from the layered to rock-salt structure and the microcrack evolution. When pairing this modified NMCA cathode at high loading mass (>450 g m⁻² for double side deposition) with the Si/C composite anode in the standard 18,650 cylinder-type cells, the prototype realizes the simultaneous robust capacity retention (~ 85% for 1000 cycles at 0.5 C), practical energy density of ~ 245.8 Wh kg⁻¹, effective mitigation of the self-discharge process at the elevated temperatures as well as 92% capacity retention even upon the operation at -20 °C. The scalability of our proposed modification strategy enables the feasible practical use of NMCA cathode within a broader temperature range.