Electrocrystallized lithuim metal, method for producing the same, and lithium secondary battery

A method for producing crystalline metal lithium with a polygonal surface shape consisting of the steps of:

• disposing in opposition to each other a metal substrate as a cathode and an ion source as an anode that electrochemically frees lithium ions, in a lithium ion-conductive non-aqueous liquid electrolyte including, as its solvent, at least one member selected from the group consisting of tetrahydrofuran derivatives represented by the formula:
• ##STR3## wherein R.sub.1 =C.sub.m H.sub.2m+1, and R.sub.2 =C.sub.n H.sub.2n+1, and m and n do not represent 0 at the same time and 1,3-dioxolan derivatives represented by the formula:. ##STR4## wherein R.sub.1 =C.sub.m H.sub.2m+m, and R.sub.2 =C.sub.n H.sub.2n+1, and m and n do not represent 0 at the same time, and
• passing a cathode current through said metal substrate to deposit lithium with a polygonal surface shape on said metal substrate.

A non-aqueous liquid electrolyte lithium secondary battery comprising:

• a rechargeable positive electrode,
• a negative electrode consisting of metal lithium with a polygonal surface shape deposited on a metal substrate by electrolysis of a lithium ion-conductive non-aqueous liquid electrolyte, and
• a lithium ion-conductive non-aqueous liquid electrolyte.