Lithium Dendrite Growth through Solid Block Copolymer Electrolyte Membranes

Polystyrene-block-poly(ethylene oxide) copolymer electrolytes, which have been shown to prolong the life of lithium metal cells by partially suppressing lithium dendrite growth, were used in X-ray tomography experiments to study lithium plating. Diblock copolymers of high modulus and molecular weight were synthesized, and their nanostructures and electrochemical properties were characterized upon addition of lithium salt. X-ray tomography was used to observe lithium metal plating through these solid polymer electrolyte membranes under a range of electrochemical conditions: regimes of lithium plating behavior as a function of current density through the block copolymer electrolyte were identified. Successful prevention of lithium dendrite growth would enable the wide use of lithium metal as an anode material in next-generation batteries.