Alternate Synthesis Method for High-Performance Manganese Rich Cation Disordered Rocksalt Cathodes

Cation-disordered rocksalt (DRX) cathodes have recently emerged as a promising class of cobalt-free, high-capacity cathodes for lithium-ion batteries. To facilitate their commercialization, the development of scalable synthesis techniques providing control over composition and morphology is critical. To this end, a sol-gel synthesis route to prepare Mn-rich DRX cathodes with high capacities is presented here. Several compositions with varied Mn content and nominal F doping are successfully prepared using this technique. In-situ X-ray diffraction measurements demonstrate that DRX formation proceeds at moderate temperature (800 degrees C) through the sol-gel route, which enables intimate mixing among reactive intermediate phases that form at lower temperatures. All synthesized compositions possess cation short-range order, as evidenced by neutron pair distribution function and electron diffraction analysis. These DRX materials demonstrate promising electrochemical performance with reversible capacities up to 275 mAh g. Compared to the baseline oxide (Li1.2Mn0.4Ti0.4O2), the Mn-rich compositions exhibit improved cycling stability, with some showing an increase in capacity upon cycling. Overall, this study demonstrates the feasibility of preparing high-capacity DRX cathodes through a sol-gel based synthesis route, which may be further optimized to provide better control over the product morphology compared to traditional synthesis methods.

Automated summary

This study presents a sol-gel synthesis route to prepare high-capacity cation-disordered rocksalt (DRX) cathodes for lithium-ion batteries. The synthesized compositions possess cation short-range order and demonstrate promising electrochemical performance with improved cycling stability and increased capacity compared to the baseline oxide. The sol-gel based synthesis route offers better control over composition and morphology.