The rapid development of the industry makes the amount of plastic waste increase. The difficulty of plastic waste to be degraded makes its handling important to avoid environmental pollution. This research converts plastic waste into activated carbon with to increase the economic value by apply the activated carbon as an anode battery additive. Li4Ti5O12 has advantages as a lithium ion battery such as a good level of safety and thermal stability but poor conductivity. The recycled carbon is activated using NaOH to obtain a porous structure that can increase the conductivity of the LTO/C composite. The activated carbon itself has conductivity of 9,65.10-5 S/m. The effect of activated carbon to the overall battery performance was being studied in this research. This study synthesized LTO/C using the ball-milling method with variations of 90 minutes, 120 minutes, and 150 minutes milling to determine the optimum composite synthesis time for the battery. The EIS test showed that the addition of activated carbon was able to increase the LTO conductivity. Based on the results of EIS, CV and CD the optimal ball mill time is 90 minutes to produce a battery with the best performance and has the lowest resistance and a specific capacity of 149,8 Ω.