Solid-state rigid-rod polymer composite electrolytes with nanocrystalline lithium ion pathways

Developing safe electrolytes compatible with high-energy-density electrodes is key for the next generation of lithium-based batteries. Stable solid-state rigid-rod polymer composite electrolytes with nanocrystalline lithium ion pathways are now proposed. A critical challenge for next-generation lithium-based batteries lies in development of electrolytes that enable thermal safety along with the use of high-energy-density electrodes. We describe molecular ionic composite electrolytes based on an aligned liquid crystalline polymer combined with ionic liquids and concentrated Li salt. This high strength (200 MPa) and non-flammable solid electrolyte possesses outstanding Li+ conductivity (1 mS cm(-1) at 25 degrees C) and electrochemical stability (5.6 V versus Li|Li+) while suppressing dendrite growth and exhibiting low interfacial resistance (32 omega cm(2)) and overpotentials (<= 120 mV at 1 mA cm(-2)) during Li symmetric cell cycling. A heterogeneous salt doping process modifies a locally ordered polymer-ion assembly to incorporate an inter-grain network filled with defective LiFSI and LiBF4 nanocrystals, strongly enhancing Li+ conduction. This modular material fabrication platform shows promise for safe and high-energy-density energy storage and conversion applications, incorporating the fast transport of ceramic-like conductors with the superior flexibility of polymer electrolytes.

Automated summary

The proposed stable solid-state polymer composite electrolyte shows promise for addressing the key challenge of electrolyte compatibility with high-energy-density electrodes in the next generation of lithium-based batteries. This electrolyte possesses outstanding Li+ conductivity and electrochemical stability, potentially enabling safe and high-energy-density energy storage and conversion applications.