System and methods for controlled depowering of automobile batteries

1. A method of controlled battery depowering, comprising:

providing an automotive battery to be depowered;

providing a substantially non-ionic depowering medium comprising between 1 and 25 weight percent carbon conductor uniformly dispersed in a substantially non-ionic aqueous medium;

contacting positive and negative terminals of the battery with the depowering medium; and

maintaining contact between the depowering medium and the positive and negative terminals for a period of time sufficient to depower the battery;

wherein increases in battery temperature and evolution of H 2 , O 2 , and Cl 2 are controlled during depowering.

2. A method according to claim 1 , comprising forming the depowering medium by (i) providing the substantially non-ionic aqueous medium; (ii) providing the carbon conductor; (iii) dispersing the carbon conductor in the substantially non-ionic aqueous medium; and (iv) mixing to form a uniform mixture.

3. A method according to claim 1 , wherein the battery is selected from lithium-ion, lead acid, and nickel-metal hydride batteries.

4. A method according to claim 1 , wherein the aqueous medium comprises between 10 and 50 weight percent ethylene glycol.

5. A method according to claim 1 , wherein the aqueous medium comprises between 1 and 15 weight percent of dispersing agent selected from starch, styrene-butadiene-rubber, sodium carboxymethyl cellulose, polyethylene oxide, polyvinyl alcohol, and combinations thereof.

6. A method according to claim 1 , wherein the carbon conductor is selected from carbon black, carbon fiber, and combinations thereof.

7. A method according to claim 6 , wherein the depowering medium has a viscosity of between 100 and 50,000 centipoise.

8. A method according to claim 6 , wherein the depowering medium has a resistivity of between 0.5 and 100 ohms centimeters.

9. A method of controlled battery depowering, comprising:

providing an automotive battery to be depowered disposed within a container configured to receive a fluid, the battery selected from lithium-ion, lead acid, and nickel-metal hydride batteries;

providing a substantially non-ionic depowering medium comprising between 1 and 25 weight percent carbon conductor uniformly dispersed in a substantially non-ionic aqueous medium, the carbon conductor selected from carbon black, carbon fiber, and combinations thereof;

supplying the depowering medium to the container such that positive and negative terminals of the battery are contacted with the depowering medium; and

maintaining contact between the depowering medium and the positive and negative terminals for a period of time sufficient to depower the battery;

wherein increases in battery temperature and evolution of H 2 , O 2 , and Cl 2 are controlled during depowering.

10. A method according to claim 9 , comprising forming the depowering medium by (i) providing the substantially non-ionic aqueous medium; (ii) providing the carbon conductor; (iii) dispersing the carbon conductor in the substantially non-ionic aqueous medium; and (iv) mixing to form a uniform mixture.

11. A method according to claim 9 , wherein the aqueous medium comprises between 10 and 15 weight percent ethylene glycol.

12. A method according to claim 9 , wherein the aqueous medium comprises between 1 and 15 weight percent of one or more dispersing agents selected from starch, styrene-butadiene-rubber, sodium carboxymethyl cellulose, polyethylene oxide, and polyvinyl alcohol.

13. A method according to claim 9 , wherein the depowering medium has a viscosity of between 100 and 50,000 centipoise and a resistivity of between 0.5 and 100 ohm centimeters.

14. A method according to claim 9 , wherein the container comprises one or more fluid inlets disposed in, or proximate to, a bottom portion of the container; and the depowering medium is supplied to the container through the one or more fluid inlets such that a battery body is contacted with the depowering medium prior to the positive and negative terminals being contacted with the depowering medium.

15. A system for controlled battery depowering, comprising:

a substantially non-ionic depowering medium comprising between 1 and 25 weight percent carbon conductor uniformly dispersed in a substantially non-ionic aqueous medium; and

a container comprising a bottom portion and one or more fluid inlets disposed in, or proximate to, the bottom portion, the container being configured to (i) receive an automotive battery to be depowered, such battery having a body, a positive terminal, and a negative terminal; and to (ii) receive the depowering medium through the one or more fluid inlets such that the battery body is contacted with the depowering medium prior to the positive and negative battery terminals being contacted with the depowering medium.

16. A system according to claim 15 , wherein the depowering medium comprises between 10 and 50 weight percent ethylene glycol.

17. A system according to claim 15 , wherein the depowering medium comprises between 1 and 15 weight percent of one or more dispersing agents selected from starch, styrene-butadiene-rubber, sodium carboxymethyl cellulose, polyethylene oxide, and polyvinyl alcohol.

18. A system according to claim 15 , wherein the carbon conductor is selected from carbon black, carbon fiber, and combinations thereof.

19. A system according to claim 18 , wherein the depowering medium has a viscosity of between 100 and 50,000 centipoise and a resistivity of between 0.5 and 100 ohm centimeter.