High power and thermal-stable of graphene modified LiNi0.8Mn0.1Co0.1O2 cathode by simple method for fast charging-enable lithium ion battery

The use of batteries in modern electronic devices and electric cars is becoming increasingly important. Batteries with high energy density, high rate and cycle capability, as well as operational safety, are in high demand today. The cathode of a lithium-ion battery is a part that significantly affects the performance of the battery. LiNiMnCoO2 (NMC) cathode, especially in the composition of LiNi0.8Mn0.1Co0.1O2 (NMC811), has high specific capacity but not high thermal and electrical conductivity stability. To improve the temperature stability and performance of the battery, conductive elements such as graphene can be added. The addition of graphene can increase battery performance due to its high electrical conductivity characteristics. In this study, the addition of graphene on NMC cathode through a simple solid-state technique along with direct mixing was shown to improve the cathode characteristics. The addition of graphene on the NMC cathode also proved to be capable of improving the cycle stability and rate capability. The retention capacity is 95.83 %, higher than that of the cathode without graphene modification, which is 92.27 % after 100 cycles with 1C current, and comparable to the capability of commercial batteries. The ability to work under rapid charge and discharge conditions was also well demonstrated with a capacity drop of 5.44 % over 200 cycles at a charge and discharge current of 5C. The addition of graphene was also shown to improve the safe use of NMC batteries. With the test at 5C current, the highest temperature of the battery was 46.52 degrees C, which is still considered safe for the operation of lithium ion based batteries at high currents. In this research, the use of a simple solid-state method to mix the graphene with NMC811 cathode is proven to be able to produce lithium-ion batteries with superior performance. This offers ease in terms for use in large-scale production of cathode preparation that can produce high-performance cathodes.