ELECTRODE FOR ENERGY STORAGE DEVICE

1 . A method of making an active electrode material, the method comprising:

providing activated carbon having between about 70 and 98 percent microporous activated carbon particles of a total amount of activated carbon by weight and between about 2 and 30 percent mesoporous activated carbon particles of the total amount of activated carbon by weight;

providing binder; and

mixing the activated carbon and the binder to obtain a mixture.

2 . A method in accordance with claim 1 , wherein the providing activated carbon operation comprises providing activated carbon having between about 80 and 98 percent microporous activated carbon particles of the total amount of activated carbon by weight and between about 2 and 20 percent mesoporous activated carbon particles of the total amount of activated carbon by weight.

3 . A method in accordance with claim 1 , wherein the operation of providing the activated carbon includes providing the total amount of activated carbon in amount of between about 80 and about 97 percent of the mixture by weight, and wherein the operation of providing the binder includes providing binder in amount of between about 3 and about 20 percent of the mixture by weight.

4 . A method in accordance with claim 1 , further comprising conductive particles.

5 . A method in accordance with claim 4 , wherein the conductive particles comprise conductive carbon.

6 . A method in accordance with claim 1 , wherein the operation of mixing includes dry blending the activated carbon and the binder.

7 . A method in accordance with claim 1 , wherein the operation of mixing is performed without processing additives.

8 . A method in accordance with claim 1 , wherein the operation of mixing is performed with processing additives.

9 . A method in accordance with claim 1 , further comprising forming an electrode film from the mixture.

10 . An electrode comprising:

a current collector; and

a film of active electrode material attached to the current collector, wherein the active electrode material comprises a total amount of activated carbon having between about 70 and 98 percent microporous activated carbon particles of the total amount of activated carbon by weight and between about 2 and 30 percent mesoporous activated carbon particles of the total amount of activated carbon by weight.

11 . The electrode of claim 10 , wherein the total amount of activated carbon has between about 70 and 98 percent microporous activated carbon particles of the total amount of activated carbon by weight and between about 2 and 30 percent mesoporous activated carbon particles of the total amount of activated carbon by weight.

12 . The electrode of claim 10 , wherein the active electrode material includes activated carbon and a binder, wherein the total amount of activated carbon is in an amount of between about 80 and about 97 percent of the film by weight, and wherein the binder is in an amount of between about 3 and about 20 percent of the film by weight.

13 . The electrode of claim 10 , wherein the active electrode material is formed from a mixture of activated carbon and binder.

14 . An electrochemical double layer capacitor comprising:

a first electrode comprising a first current collector and a first film of active electrode material, the first film comprising a first surface and a second surface, the first current collector being attached to the first surface of the first film, wherein the first film comprises a total amount of activated carbon having between about 70 and 98 percent microporous activated carbon particles of the total amount of activated carbon by weight and between about 2 and 30 percent mesoporous activated carbon particles of the total amount of activated carbon by weight;

a second electrode comprising a second current collector and a second film of active electrode material, the second film comprising a third surface and a fourth surface, the second current collector being attached to the third surface of the second film;

a porous separator disposed between the second surface of the first film and the fourth surface of the second film;

a container;

an electrolyte;

wherein:

the first electrode, the second electrode, the porous separator, and the electrolyte are disposed in the container;

the first film is at least partially immersed in the electrolyte;

the second film is at least partially immersed in the electrolyte;

the porous separator is at least partially immersed in the electrolyte;

each of the first and second films include a mixture of carbon and binder with a resulting iron content of about equal to or not exceeding about 20 parts per million.

15 . The capacitor of claim 14 , wherein the films are attached to respective collectors via a conductive adhesive layer.

16 . The capacitor of claim 14 , wherein the total amount of activated carbon has between about 70 and 98 percent microporous activated carbon particles of the total amount of activated carbon by weight and between about 2 and 30 percent mesoporous activated carbon particles of the total amount of activated carbon by weight.

17 . The electrode of claim 14 , wherein the active electrode material includes activated carbon and a binder, wherein the total amount of activated carbon is in an amount of between about 80 and about 97 percent of the first film by weight, and wherein the binder is in an amount of between about 3 and about 20 percent of the first film by weight.

18 . The capacitor of claim 14 , wherein the active electrode material is formed from a mixture of activated carbon and binder.