Electrochemical and structural effects of in situ Li2O extraction from Li2MnO3 for Li-Ion batteries

Li2MnO3 is an attractive cathode material due to its low cost, nontoxicity and potentially high capacity. However, its electrochemical inactivity, its poor electronic conductivity, and uncertainty about its underlying mechanism have limited its development. In this work, an in situ technique for extraction of Li and O during deposition of the thin film cathode is developed to investigate structural and electrochemical effects in a controlled fashion. MnO2 has been observed in samples with severe O and Li deficiency (capacity of 115 mAh g(-1)), while Li2MnO3 cathodes with slight excess of O and Li (capacity of 225 mAh g(-1)) can be synthesized by tuning growth conditions appropriately. Formation of a MnO2 phase, especially in Li and O deficient structures, could be a possible reason for irreversible capacity loss in Li2MnO3 related materials. Further investigation into stoichiometric and microstructure variations enabled by this technique allows rapid investigation of Li2MnO3 as well as other Li-rich composites.

Scalable synthesis and surface stabilization of Li2MnO3 NWs as high rate cathode materials for Li-ion batteries

Schematic (on the left) showing LiMn₂O₄ protective shell on (Li₂O)_x MnO₂ NWs with layered structure. Graph (on the right) showing high capacity retention and high columbic efficiency with this architecture after 100 cycles.

Enhanced electrochemical performance and thermal stability of a CePO4-coated Li1.2Ni0.13Co0.13Mn0.54O2 cathode material for lithium-ion batteries

CePO₄ coating via a simple precipitation method enhances the thermal stability of the layered Li_1.2Ni_0.13Co_0.13Mn_0.54O₂ cathode material.