High‐Nickel Heterostructured Cathodes with Local Stoichiometry Control for High‐Voltage Operation

• DOI: 10.1002/sstr.202300236
• Publication Date: 2023-09-06T03:13:12Z
• Authors: Chong Yin; Mingyuan Ge; Youngmin Chung; Jianming Bai; Wah-Keat Lee; Kim Kisslinger; Steven N. Ehrlich; Xianghui Xiao; Bao Qiu; Stephen E. Trask; Alison R. Dunlop; Andrew N. Jansen; Zhaoping Liu; Youngho Shin; Feng Wang
• Keywords: Stoichiometry; High Voltage; High energy

The growing demand for lithium‐ion batteries to power electric vehicles and other energy‐dense devices continues fuel the need cathodes of increasingly higher nickel in cathodes. relentless pursuit high Ni content, however, raises concerns on compromising cell lifetime safety, especially under high‐voltage operation. Alternative traditional design uniform or core–shell composition, we report a rational control local stoichiometry high‐Ni cathodes, enabling their thermal cycling stabilities—up 258 °C at fully charged state 91.4% capacity retention 100 cycles between 2.7 4.4 V. Multimodal synchrotron X‐ray characterization unveils heterostructure secondary particles, featuring core (LiNi 0.90 Mn 0.05 Co O 2 ) covered by thin Ni‐gradient layer that remains stable over prolonged due suppressed oxygen release structural deterioration. This work underlines, intricate interplay redox reactions stabilizing operation while ensuring safety.