Carbothermal treatment was used to improve the discharge rate performance of primary lithium/carbon monofluoride (Li/CF x with x =1) batteries. The treatment was carried out by heating a mixture of CF x and carbon black (CB) just below the decomposition temperature of CF x under nitrogen for 2h. In the treatment, poly(vinylidene fluoride-co-hexafluoropropylene) (Kynar) was used as a fluorinated polymer binder to press the CF x /CB mixture into pellets. It was shown that the content of Kynar significantly affected the discharge performance of the resulting treated-CF x (T-CF x ). This can be attributed to the catalytic effect of HF formed by the pyrolysis of Kynar on the decomposition of CF x and on the reaction of CB with the volatile fluorocarbons formed by the decomposition of CF x . The discharge performance of T-CF x cathode was also affected by the temperature of carbothermal treatment and by the ratio of CF x to CB. In this work the best result was obtained from a treatment conducted at 470°C on a 87CF x /10CB/3Kynar (by weight) mixture. In the discharge condition of C/5 and 20°C, the Li/CF x cell with such-obtained T-CF x cathode showed about 95mV higher voltage than the control cell while retaining nearly the same specific capacity. Impedance analyses indicate that the improved discharge performance is mainly attributed to a reduction in the cell reaction resistance (R cr) that includes an ohmic resistance related to the ionic conductivity of the discharge product shell and a Faradic resistance related to the processes of charge-transfer and Li+ ion diffusion in the CF x reaction zone.