Dendrite-intercepting layer for alkali metal secondary battery

A process for producing a dendrite penetration-resistant layer for a rechargeable alkali metal battery layer, said process comprising (a) preparing a working electrode containing a porous structure of multiple graphene sheets or platelets or exfoliated graphite flakes;

• (b) preparing a counter electrode containing lithium or sodium metal or alloy;
• (c) bringing said working electrode and said counter electrode in contact with an electrolyte containing a solvent and a lithium salt or sodium salt dissolved in said solvent;
• and (d) applying a current or voltage to said working electrode and said counter electrode to induce an electrochemical oxidative decomposition and/or a reductive decomposition of said electrolyte for forming one or more lithium- or sodium-containing species that are chemically bonded to said multiple graphene sheets or platelets or exfoliated graphite flakes to produce said dendrite penetration-resistant layer.

A process for producing a dendrite penetration-resistant layer for a rechargeable alkali metal battery, said process comprising (a) preparing an alkali metal battery cell comprising an anode alkali metal layer, a layer of graphene sheets or exfoliated graphite flakes, a porous separator layer, and a cathode layer, wherein said layer of graphene sheets or exfoliated graphite flakes is laminated between said alkali metal layer and said porous separator layer and said porous separator layer is disposed between said layer of graphene sheets or exfoliated graphite flakes and said cathode layer;

• and (b) subjecting said battery cell to a voltage/current treatment that induces electrochemical reductive and/or oxidative decomposition to form said lithium- and/or sodium-containing species that are chemically bonded to said graphene sheets or exfoliated graphite flakes to form the dendrite penetration-resistant layer in said battery cell.