Secondary battery and method of producing the secondary battery

1. A secondary battery, comprising:

an electric cell layer including a stack structure sequentially including:

a positive electrode layer,

a separator layer, and

a negative electrode layer having an electrolyte higher in conductivity than an electrolyte of at least one of the separator layer and the positive electrode layer,

wherein the electrolyte of each of the negative electrode layer and the separator layer is a liquid material, and the electrolyte of the positive electrode layer is a polymer.

2. A secondary battery, comprising:

an electric cell layer including a stack structure sequentially including:

a positive electrode layer,

a separator layer, and

a negative electrode layer having an electrolyte higher in conductivity than an electrolyte of at least one of the separator layer and the positive electrode layer,

wherein the electrolyte of the negative electrode layer is a liquid material and the electrolyte of each of the separator layer and the positive electrode layer is a polymer.

3. The secondary battery according to claim 2 , wherein the conductivity of the electrolyte of the negative electrode layer is higher than the conductivity of the electrolyte of the separator layer.

4. The secondary battery according to claim 2 , wherein at least the positive electrode layer and the separator layer have a contact with each other.

5. The secondary battery according to claim 2 , wherein:

the positive electrode layer and the separator layer have a contact with each other, and

the negative electrode layer and the separator layer have a contact with each other.

6. The secondary battery according to claim 2 , wherein the negative electrode layer includes a plurality of layers which are disposed in a direction of a thickness of the negative electrode layer and are different from each other in voidage.

7. The secondary battery according to claim 2 , including at least one of the following first and second structures:

a first structure including the positive electrode layer including:

a positive electrode current collector having a groove defining a width and a depth, and

a positive electrode active material layer formed on the positive electrode current collector,

wherein each of the width and the depth of the groove of the positive electrode current collector is less than or equal to 10% of an average particle diameter of the positive electrode active material layer, and

a second structure including the negative electrode layer including:

a negative electrode current collector having a groove defining a width and a depth, and

a negative electrode active material layer formed on the negative electrode current collector,

wherein each of the width and the depth of the groove of the negative electrode current collector is less than or equal to 10% of an average particle diameter of the negative electrode active material layer.

8. The secondary battery according to claim 7 , including at least one of the following third and fourth structures:

a third structure including the positive electrode layer including:

a positive electrode current collector, and

a positive electrode active material layer formed on the positive electrode current collector and having a groove, and

a fourth structure including the negative electrode layer including:

a negative electrode current collector, and

a negative electrode active material layer formed on the negative electrode current collector and having a groove.

9. A secondary battery comprising:

an electric cell layer including a stack structure sequentially including:

a positive electrode layer,

a separator layer, and

a negative electrode layer having an electrolyte higher in conductivity than an electrolyte of at least one of the separator layer and the positive electrode layer,

wherein the electrolyte of the negative electrode layer is a liquid material, and the electrolyte of each of the separator layer and the positive electrode layer is a polymer, and

wherein the negative electrode layer comprises a negative electrode active material, wherein the negative electrode active material comprises a carbon material.

10. The secondary battery according to claim 9 , wherein the carbon material is selected from the group comprising of natural graphite, artificial graphite, carbon black, active carbon, carbon fiber, coke, soft carbon, and hard carbon.

11. The secondary battery according to claim 1 , wherein a conductivity of at least one of the separator layer and the positive electrode layer is 1/100 to ½ relative to the conductivity of the electrolyte of the negative electrode layer.

12. The secondary battery according to claim 2 , wherein a conductivity of at least one of the separator layer and the positive electrode layer is 1/100 to ½ relative to the conductivity of the electrolyte of the negative electrode layer.

13. The secondary battery according to claim 9 , wherein a conductivity of at least one of the separator layer and the positive electrode layer is 1/100 to ½ relative to the conductivity of the electrolyte of the negative electrode layer.