Study on storage properties of spinel-like Li1.68Mn1.6O3.7F0.3 cathode material for high energy density lithium-ion batteries

• The impact of humidity and CO 2 on the storage performance of LMOF was studied firstly. • Initial capacity of LMOF decreased from 263.5 to 208.6 mAh/g after 10 days air storage. • Moisture and bicarbonate species are key factors for the storage stability of the LMOF. The novel spinel-like Li 1.68 Mn 1.6 O 3.7 F 0.3 (LMOF) cathode material exhibits a high discharge specific capacity and exceptional rate performance, attributed to its distinctive lithium-ion diffusion mechanism and partially ordered structural characteristics. Nonetheless, the application of this material is highly sensitive to environmental conditions and its initial discharge capacity decreased from 263.5 mAh g −1 to 208.6 mAh g −1 after 10 days storage in air. However, the mechanisms influencing its storage stability remain unclear. This study systematically elucidates that moisture and CO 2 in the air are critical factors contributing to the degradation of its storage stability, with the formation of bicarbonate species particularly leading to significant deterioration in electrochemical performance. These findings offer valuable insights for advancing the practical application of LMOF.