High-energy lithium batteries based on single-ion conducting polymer electrolytes and Li[Ni0.8Co0.1Mn0.1]O2 cathodes

Single-ion conducting polymer electrolytes are considered ideal for suppressing dendritic lithium deposition, but so far suffered instability at elevated potentials and, thus, incompatibility with next-generation high-energy cathodes such as Ni-rich Li[Ni1-x-yCoxMny]O2 (NCM(1-x-y)xy).

Herein, we show that the thoughtful design of electrolytes based on multi-block co-poly(arylene ether sulfone)s and incorporating suitable “molecular transporters” (such as propylene carbonate) may, in fact, enable the realization of high-energy lithium-metal batteries employing, for the first time, NCM811-based positive electrodes. These batteries can be cycled with high reversible capacity at various temperatures, including 20 °C and even 0 °C, for more than 500 cycles without substantial capacity fading when applying an optimized charging mode. The careful electrochemical characterization and ex situ investigation of the electrode/electrolyte interfaces reveals, moreover, that the use of such single-ion conductor successfully inhibits dendritic lithium metal deposition, while particular care has to be taken for the interface between the electrolyte and the NCM811 cathode.

https://doi.org/10.1016/j.nanoen.2020.105129