High Energy Density Flake-Type LiMn 0.8 Fe 0.2 PO 4

Abstract

Low surface area and dense LiMn 0.8 Fe 0.2 PO 4 /graphite composite particles (F-LMFP2) made with an all-dry process are described that demonstrate superior electrochemical performance and higher volumetric energy densities than conventional LiMn 0.8 Fe 0.2 PO 4 (LMFP). The F-LMFP2 material exhibited a flake-like morphology, resulting in a low surface area (3.93 m 2 g −1 ) and excellent packing properties, allowing calendered electrodes to reach a high coating density of 2.26 g ml -1 without electrode delamination. When cycled in Li half-cells, calendered F-LMFP2 electrodes demonstrated superior capacity retention (131.3 mAh g −1 /100 cycles), lower polarization, improved rate performance than conventional LMFP, which suffered from rapid capacity fade when densified. Moreover, the ability of F-LMFP2 to be highly densified, while retaining good electrochemical performance resulted in a high volumetric energy density of 1144 Wh l −1 to be obtained, representing a 40% increase over conventional LMFP. These results highlight the potential of dry particle processing techniques to produce high-density olivine-based cathodes, enabling cost-effective and sustainable Li-ion cells with high volumetric energy density.