Dioxolane as a proctector for lithium electrodes

A battery cell electrolyte, comprising:

• a) a main solvent having the chemical formula R1(CH2CH2O)nR2, where n ranges between 1 and 10, R1 and R2 are different or identical groups selected from the group consisting of alkyl, alkoxy, substituted alkyl, and substituted alkoxy groups;
• b) a first co-solvent comprising dioxolane;
• and
• c) a second co-solvent having a donor number of at least about 13.

A negative electrode, comprising:

• a) a lithium material;
• and
• b) a dioxolane-based film coating said lithium material, said film formed by treating said lithium material with dioxolane;
• wherein said electrode is outside a battery cell.

A battery cell comprising:

• a) a negative lithium electrode;
• b) a positive electrode comprising an electrochemically active material;
• c) an electrolyte including a
• i) a main solvent of an electrolyte solvent mixture, having the chemical formula R1(CH2CH2O)nR2, where n ranges between 1 and 10, R1 and R2 are different or identical groups selected from the group consisting of alkyl, alkoxy, substituted alkyl, and substituted alkoxy groups;
• ii) a dioxolane co-solvent, comprising no more than 30% by volume of the electrolyte solvent mixture;
• and
• iii) a second co-solvent having a donor number of at least about 13.

A battery cell comprising:

• b) a negative lithium electrode;
• b) a positive electrode comprising an electrochemically active material;
• c) an electrolyte including a
• i) a main solvent of an electrolyte solvent mixture, having the chemical formula R1(CH2CH2O)nR2, where n ranges between 1 and 10, R1 and R2 are different or identical groups selected from the group consisting of alkyl, alkoxy, substituted alkyl, and substituted alkoxy groups;
• and
• ii) a dioxolane co-solvent comprising no more than 30% by volume of the electrolyte solvent mixture wherein said electrolyte is in a gel state.

A batters cell comprising:

• c) a negative lithium electrode;
• b) a positive electrode comprising an electrochemically active material;
• c) an electrolyte including a
• i) a main solvent of an electrolyte solvent mixture, having the chemical formula R1(CH2CH2O)nR2, where n ranges between 1 and 10, R1 and R2 are different or identical groups selected from the group consisting of alkyl, alkoxy, substituted alkyl, and substituted alkoxy groups;
• and
• ii) a dioxolane co-solvent, comprising no more than 30% by volume of the electrolyte solvent mixture wherein said electrolyte is in a solid state.

A battery cell comprising:

• a) a negative lithium electrode, comprising,
• i) a lithium material, and
• ii) a film coating said lithium material, said film formed by treating said lithium material with dioxolane prior to incorporation of said electrode into a battery cell;
• b) a positive electrode comprising an electrochemically active material;
• and
• c) an electrolyte including
• i) a solvent having the chemical formula R1(CH2CH2O)nR2, where n ranges between 1 and 10, R1 and R2 are different or identical groups selected from the group consisting of alkyl, alkoxy, substituted alkyl, and substituted alkoxy groups
• ii) a co-solvent having a donor number of at least about 13.

A method of making a protected lithium electrode battery cell, comprising:

• a) treating a lithium material with dioxolane to form a negative electrode having a protective film;
• b) forming a positive electrode comprising an electrochemically active material;
• and
• c) combining said negative and positive electrodes with an electrolyte following the treating of said lithium material.