High-Voltage Performance Enhancement of Nickel-Rich Cathode through Improved Binding Ability of Designed Binder

As mobile electronics and electric vehicles become essential in our lives, the specific energy density of a lithium-ion battery is one of the criteria that determines the quality of a battery and customers’ use range. Cathode is the one that primarily determines the capacity and energy density of the battery, and consists of active material, binder and carbon black. Nickel-rich layered oxides such as LiNi0.8Co0.1Mn0.1O2 (NCM811) are promising high-capacity cathode active materials, and its reversible capacity increases more by charging to higher cut-off voltages than the conventional 4.2 V. We observed that NCM811 cathode fabricated with commercial polyvinylidene fluoride binder has an unstable interface to electrolyte under high cut-off charge voltages and undergoes drastic structural changes during cycling in particular at elevated temperature, leading to capacity fade and reduced lifespan of the battery. In order to acquire a high reversible capacity and enhanced cycling performance with NCM811 cathode by mitigating the problems, we have designed an unique and functional high-voltage binder and make the combination with NCM811. In the meeting, we are going to report improved thermal stability and cycling performance of the designed binder-assisted cathode. Acknowledgement This research was supported by the Ministry of SMEs and Startups (S2788978) of Korea, National Research Foundation grant funded by the Korean Ministry of Science and ICT (No. 2019R1A2C1084024) and Creative Human Resource Development Consortium for Fusion Technology of Functional Chemical/Bio Materials of BK Plus program by Ministry of Education of Korea.