Co- free gradient lithium- rich cathode for high- energy batteries with optimized cyclability

• 成果类型: Article
• 署名作者: Yang, Haotian; Wang, Lihang; Li, Yuqiang; Zhuo, Zengqing; Wu, Tianhao; Liu, Jie; Xu, Ligang; Du, Haozhe; Liu, Shiqi; Wu, Lingqiao; Zhao, Shu; Tang, Mingxue; Yang, Wanli; Yu, Haijun
• 署名单位: Beijing University of Technology; Beijing University of Technology; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; University of Science & Technology Beijing
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9256
• DOI: 10.1073/pnas.2412460121
• 发表日期: 2024-12-10
• 关键词: voltage-fade; li-ion; STABILITY; origin; redox; mechanism; nmr; mn; ni

摘要

Lithium- rich layered oxides (LLOs) hold the promise for high- energy battery cathodes. However, its application has been hindered by voltage decay associated with irreversible reactions at high voltages despite decades of intensive efforts. Here, we first theoretically studied the molecular orbitals of Mn-based Li- rich configurations. We found that the it- bond ring formed within the LiMn6 structure could participate in stable redox reactions as one unit, but Co could disrupt its symmetry. We thus designed and synthesized Co- free concentration- gradient LLOs (CF- CG-LLOs) materials. The combination of concentration gradient and Co removal leads to exceptional capacity retention without any fading over 100 cycles of the pouch cell. More importantly, it exhibits an extraordinarily low voltage decay of 0.15 mV/cycle, accompanied by a high Coulombic efficiency of 99.86%. This concept and demonstration of CF- CG-LLO cathodes reveal a viable avenue toward low- cost, high- energy- density battery cathodes.