Lithium-rich cation-disordered rocksalt (DRX) oxides (Li_1+x(M,M’)_1-xO₂, M = Mn and Ni, M’ = d⁰ transition metal) have been shown as promising next-generation cathode materials due to their ability to utilize redox reactions of both transition metal (TM) cations and oxygen (O) anions. However, significant performance decay upon electrochemical cycling limits their application in commercial markets. Compared to the well-known redox behavior of TM cations, O redox activities are less reversible in DRX and considered the likely cause for voltage and capacity fade observed in these materials. Partial anion substitution of oxygen by fluorine can increases redox active TM content, simultaneously reducing O redox participation and minimizing inactive TM. To fully take advantage of fluorination, however, F solubility in DRX needs to be improved. In this presentation, I will show a new synthesis approach that allows us to achieve higher F incorporation and consequently, better DRX cycling performance.