Porous Manganese Oxide Networks as High-Capacity and High-Rate Anodes for Lithium-Ion Batteries

Abstract

A mesoporous MnOx network (MMN) structure and MMN/C composites were prepared and evaluated as anodes for high-energy and high-rate lithium-ion batteries (LIB) in comparison to typical manganese oxide nanoparticle (MnNP) and graphite anodes, not only in a half-cell but also in a full-cell configuration (assembled with an NCM523, LiNi0.5Co0.2Mn0.3O2, cathode). With the mesoporous features of the MMN, the MMN/C exhibited a high capacity (approximately 720 mAh g−1 at 100 mA g−1) and an excellent cycling stability at low electrode resistance compared to the MnNP/C composite. The MMN/C composite also showed much greater rate responses than the graphite anode. Owing to the inherent high discharge (de-lithiation) voltage of the MMN/C than graphite as anodes, however, the MMN‖NCM523 full cell showed approximately 87.4% of the specific energy density of the Gr‖NCM523 at 0.2 C. At high current density above 0.2 C, the MMN‖NCM523 cell delivered much higher energy than the Gr‖NCM523 mainly due to the excellent rate capability of the MMN/C anode. Therefore, we have demonstrated that the stabilized and high-capacity MMN/C composite can be successfully employed as anodes in LIB cells for high-rate applications.