Constructing Jahn-Teller Monoclinic Boundary Network for High-Performance Ni-rich Layered Oxide Cathode Materials
DescriptionDriven by continuous expansion of electric vehicle (EV) market, demands for high-performance lithium-ion batteries (LIBs) are boosted. Layered Ni-rich LiNixCoyMnzO2 (x≥0.8, referred as Nirich NCMs) cathode materials have aroused broad attentions to be applied in EV-LIBs due to their high capacity and reduced cost. However, the structural instability of the Ni-rich cathodes induces severe capacity decay upon cycling, which hinders this promising material from commercial success. To extend the cycle life, traditional efforts mainly focus on coating protective layers, yet this strategy always fails to fully address the intrinsic instability of the layered structure, and the coating layers are always structurally incompatibility with the host Ni-rich NCMs, which will introduce additional challenges. Here in this project, we try to tackle this long-standing issue by constructing Jahn-Teller functionalized monoclinic boundary networks onto the hexagonal primary grains. Our preliminary results demonstrate that the Jahn-Teller network could be constructed by oxidizing co-precipitated precursors, and the resulted Ni-rich cathodes benefit from hexagonal core for high capacity and monoclinic boundary network for high stability. It is expected that the optimized Ni-rich NCM cathodes could enable excellent overall electrochemical performance, such as discharge capacity > 200 mAh g-1 , columbic efficiency > 99.9 % and capacity retention > 96% after 100 cycles. In addition, the structural-performance relationship of JahnTeller Ni-rich NCMs will be also studied and clarified. The final objective of this project is to assemble an industrial-level full cell with optimized Ni-rich NCM cathode and commercial anode, which can be expected to meet the industrial requirement.
|Effective start/end date||1/01/23 → …|