Search for a command to run...
The effectiveness of introducing succinic anhydride as an electrolyte additive for high-energy lithium-ion battery cells based on LiNi0.6Mn0.2Co0.2O2/graphite (NMC622/graphite), which provide an optimal balance between specific capacity and calendar life, is demonstrated. The use of vinylene carbonate and fluoroethylene carbonate as functional additives for the formation of protective layers in lithium-ion batteries based on NMC622/graphite is particularly important for operational stability and improvement of calendar life. A comparative evaluation of the effectiveness of succinic anhydride as a replacement for vinylene carbonate and fluoroethylene carbonate is carried out for the first time. A recrystallization procedure for technical-grade succinic anhydride was developed to remove critical impurities of water and succinic acid. The decomposition of electrolyte additives is found to occur in the range of 2.4–2.8 V prior to the decomposition of carbonate solvents, ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, resulting in the formation of protective interphase layers on the electrodes. A key result is the demonstration that an electrolyte containing 1 vol % succinic anhydride after recrystallization increases capacity retention to 92% after 200 cycles in lithium-ion batteries based on NMC622/graphite compared with an additive-free electrolyte. The effectiveness of succinic anhydride as an alternative to widely used vinylene carbonate and fluoroethylene carbonate is also demonstrated. The improvement in the calendar life of lithium-ion batteries based on NMC622/graphite is associated with the formation of protective interphase layers on the electrodes.