Dopamine as a Novel Electrolyte Additive for High Voltage Lithium Ion Batteries.
Dopamine, which can be electrochemically oxidized to polydopamine on cathode surface, was introduced as an electrolyte additive for high voltage lithium ion batteries (LIBs) The addition of 0.1 wt dopamine to the electrolyte led to the formation of a polydopamine containing layer on the cathode, thereby resulting in suppression of the oxidative decomposition of the electrolyte during high voltage operation (up to 4.5 V) of a LiNi1/3Co1/3Mn1/3O2/artificial graphite cell. The addition of dopamine to the electrolyte improved the capacity retention of the cell from 136 to 147 mAh g( 1) after 100 cycles at a rate of 1 C and a cutoff voltage of 4.5 V, while the cycle performance and rate capability with a cutoff voltage of 4.3 V were comparable to those of the cell without dopamine. Further evidence of the positive impact of dopamine on high voltage LIBs was the lower DC IRs and AC impedances, as well as the retention of the cathode morphology even after operation at 4.5 V.
ACS applied materials interfaces