METHOD FOR PRODUCING LITHIUM-ION, SODIUM-ION AND POTASSIUM-ION BATTERIES WITH INCREASED SAFETY

1 . A method for producing lithiated pyomelanin (LPM) comprising:

dissolving melanin in an alkaline lithium solution or in a solution comprising a mixture comprising:

LiOH; or

NaOH/KOH and a Li salt,

thereby producing an alkaline solution of lithium ions (Li + ) comprising the melanin;

reducing the alkaline lithium solution comprising the melanin using a reducing agent or using a cathode of an electrochemical cell at an electrical potential ≤0.8V;

in a reducing environment and/or in an electrical potential ≤0.8V and under anaerobic conditions, titrating the alkaline lithium solution comprising the melanin to neutral pH;

in the reducing environment and/or in the electrical potential ≤0.8V and under anaerobic conditions, dialyzing the mixture relative to dH 2 O, thereby producing a solution comprising LPM;

under anaerobic conditions, freezing the solution comprising LPM; and

lyophilizing the solution comprising LPM to remove water; thereby producing LPM.

2 . The method of claim 1 wherein the dialyzing is conducted under cold conditions.

3 . The method of claim 1 wherein the dialyzing is conducted using a low cutoff dialysis membrane or filter.

4 . A method for producing sodiated pyomelanin (SPM) comprising:

dissolving melanin in an alkaline sodium solution or in a solution comprising a mixture comprising:

NaOH; or

KOH and a sodium salt,

thereby producing an alkaline solution of sodium ions (Na+) comprising the melanin;

reducing the alkaline sodium solution comprising the melanin using a reducing agent or using a cathode of an electrochemical cell at an electrical potential ≤0.8V;

in a reducing environment and/or in an electrical potential ≤0.8V and under anaerobic conditions, titrating the alkaline sodium solution comprising the melanin to neutral pH;

in the reducing environment and/or in the electrical potential ≤0.8V and under anaerobic conditions, dialyzing the mixture relative to dH 2 O, thereby producing a solution comprising SPM;

under anaerobic conditions, freezing the solution comprising SPM; and

lyophilizing the solution comprising SPM to remove water; thereby producing SPM.

5 . The method of claim 4 wherein the dialyzing is conducted under cold conditions.

6 . The method of claim 4 wherein the dialyzing is conducted using a low cutoff dialysis membrane or filter.

7 . A method for producing potassiated pyomelanin (PPM) comprising:

dissolving melanin in an alkaline potassium solution or in a solution comprising a mixture comprising:

KOH; or

NaOH and a potassium salt,

thereby producing an alkaline solution of potassium ions (K+) comprising the melanin;

reducing the alkaline potassium solution comprising the melanin using a reducing agent or using a cathode of an electrochemical cell at an electrical potential ≤0.8V;

in a reducing environment and/or in an electrical potential ≤0.8V and under anaerobic conditions, titrating the alkaline potassium solution comprising the melanin to neutral pH;

in the reducing environment and/or in the electrical potential ≤0.8V and under anaerobic conditions, dialyzing the mixture relative to dH 2 O, thereby producing a solution comprising PPM;

under anaerobic conditions, freezing the solution comprising PPM; and

lyophilizing the solution comprising PPM to remove water; thereby producing PPM.

8 . The method of claim 7 wherein the dialyzing is conducted under cold conditions.

9 . The method of claim 7 wherein the dialyzing is conducted using a low cutoff dialysis membrane or filter.

10 . A method for producing a battery with increased safety, wherein the battery comprises an anode(−) compartment and a cathode(+) compartment, the method comprising:

providing a battery anode mixture;

providing lithiated pyomelanin (LPM), sodiated pyomelanin (SPM) and/or potassiated pyomelanin (PPM);

providing a battery electrolyte, wherein the battery electrolyte is non-aqueous or a proton-releasing chemical; and

adding the LPM, SPM and/or PPM to the battery anode mixture, thereby producing a battery anode mixture comprising the LPM, SPM and/or PPM, wherein the battery anode mixture comprising the LPM, SPM and/or PPM is in sufficiently low abundance so that when the battery is short-circuited or demand on the battery for electricity is large, heat released during discharge of the battery is less than a specific heat capacity of the battery, thereby:

increasing safety of the battery by avoiding formation of metallic lithium (Li o ), sodium (Na o ) and/or potassium (K o ) in the battery,

lowering risk of overheating of the battery and/or lowering risk of explosion of the battery, and

producing a battery with increased safety.

11 . The method of claim 10 wherein the battery anode mixture is a carbon anode mixture.

12 . The method of claim 10 wherein the LPM, SPM and/or PPM is added to and/or coated on a conductive surface of the anode compartment.