Na-Ion Battery with 180 Wh/kg and Long Cycle Life
Haibo Wang, Han Tang, Ting Lin, Hao Yu, Xi Liu, Jiao Zhang, Hao Guo, Shiyao Xia, Bingjie Zhang, Xiaobing Zhao, Zhao Chen, Bowen Wang, Fei Xie, Xingguo Qi, Yaxiang Lu, Lin Gu, Xiaohui Rong, Liquan Chen, Yong‐Sheng Hu
Abstract
High Resolution Image Download MS PowerPoint Slide Na-ion batteries are promising energy storage technologies, yet cathodes suffer from structural instability during deep cycling, leading to a trade-off between energy density and long-term life. Here, we introduce a “local electron density engineering” strategy to address this intrinsic challenge. We propose that structural degradation originates from the withdrawal of electron density from lattice oxygen by a high-valence transition metal. By incorporating stable d 10 (Zn 2+ ) and d 0 (Ti 4+ ) ions, we create an electron-rich oxygen framework that acts as an “electron buffer”, resisting this electron depletion. Reinforced further by Ca 2+ pillars in the Na + layers, our single-crystalline Na 0.96 Ca 0.02 Cu 0.038 Zn 0.053 Ni 0.409 Mn 0.315 Ti 0.185 O 2 cathode exhibits a low volume change of ∼4% under deep desodiation. In 26700 cylindrical full cells, it delivers an energy density of 181.2 Wh kg –1 and retains ∼80% capacity rentention after 1000 cycles. These results establish a new design pathway for developing ultrastable, high-energy cathode materials for next-generation Na-ion batteries.