Accelerating Li‐Ion Diffusion in LiFePO<sub>4</sub> by Polyanion Lattice Engineering

Authors: Xinxin Wang, Anyang Yu, Tian Jiang, Shijun Yuan, Qi Fan, Qingyu Xu

Published: 2024-10-10

DOI: 10.1002/adma.202410482

Source: Full article


Abstract

AbstractDespite the widespread commercialization of LiFePO4 as cathodes in lithium‐ion batteries, the rigid 1D Li‐ion diffusion channel along the [010] direction strongly limits its fast charge and discharge performance. Herein, lattice engineering is developed by the planar triangle BO33− substitution on tetrahedron PO43− to induce flexibility in the Li‐ion diffusion channels, which are broadened simultaneously. The planar structure of BO33− may further provide additional paths between the channels. With these synergetic contributions, LiFe(PO4)0.98(BO3)0.02 shows the best performance, which delivers the high‐rate capacity (66.8 mAh g−1 at 50 C) and long cycle stability (ultra‐low capacity loss of 0.003% every cycle at 10 C) at 25 °C. Furthermore, excellent rate performance (34.0 mAh g−1 at 40 C) and capacity retention (no capacity loss after 2500 cycles at 10 C) at −20 °C are realized.