Enhanced specific energy in fast-charging lithium-ion batteries negative electrodes via Ti-O covalency-mediated low potential
Jun Huang, Yang Qi, Anyi Hu, Zhu Liao, Zhengxi Zhang, Qinfeng Zheng, Zhouhong Ren, Shun Zheng, Yixiao Zhang, Xiaolong Yang, Zhenming Xu, Le Zhang, Daming Zhu, Wen Wen, Xi Liu, Akihiro Orita, Nagahiro Saito, Liguang Wang, Yongyao Xia, Liwei Chen, Jun Lü, Li Yang
Abstract
Developing lithium-ion batteries with high specific energy and fast-charging capability requires overcoming the potential-capacity trade-off in negative electrodes. Conventional fast-charging materials (e.g., Li4Ti5O12, TiNb2O7) operate at high potentials (>1.5 V vs. Li+/Li) to circumvent lithium plating, yet this compromises specific energy. A viable strategy for enhancing the specific energy is to reduce the potential while avoiding the lithium plating risk; however, the underlying mechanisms remain unclear. Here we demonstrate that enhancing Titanium-Oxygen covalency through pseudo-Jahn-Teller Effect distortion in Ruddlesden-Popper perovskites enables low-potential operation. The Li2La2Ti3O10 negative electrode exhibits a working potential of 0.5 V vs. Li+/Li with initial 139.3 mAh g−1 at 5 A g−1 and 72.9% capacity retention after 5000 cycles. Full cells with LiNi0.8Co0.1Mn0.1O2 positive electrodes deliver 3.45 V average discharge voltage-50% higher than conventional Li4Ti5O12 | |LiNi0.8Co0.1Mn0.1O2 systems-achieving 100 mAh g−1 at 4 A g−1. Mechanistic analysis reveals low Li⁺ migration barriers and stable Ruddlesden-Popper perovskite frameworks enable rapid ion transport. While graphite negative electrodes pose dendrite risks, high-potential fast-charging titanium-based alternatives limit battery energy. Here, authors develop a titanium oxide negative electrode with tailored atomic distortions that safely operates at 0.5 V vs. Li + /Li, boosting cell voltage by 50%.