SECONDARY BATTERY

Abstract

A secondary battery is provided. The secondary battery includes a positive electrode having a positive electrode active material layer provided on a positive electrode current collector, a negative electrode having a negative electrode active material layer provided on a negative electrode current collector, and an electrolyte, in which the positive electrode and the negative electrode are stacked and rolled up while placing a separator in between. A sum (A+B) of a total thickness “A” of the positive electrode current collector and the positive electrode active material layer, and a total thickness “B” of the negative electrode current collector and the negative electrode active material layer ranges from 161 μm to 220 μm. A ratio (A/B) of the total thickness “A” to the total thickness “B” ranges from 0.65 to 1.9.

Description

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic drawing showing a configuration of a non-aqueous electrolyte secondary battery according to one embodiment; and

FIG. 2 is a schematic drawing showing a configuration of a cell element of a non-aqueous electrolyte secondary battery according to one embodiment.

Claims

1. A secondary battery comprising: a positive electrode having a positive electrode active material layer provided on a positive electrode current collector;a negative electrode having a negative electrode active material layer provided on a negative electrode current collector; andan electrolyte, in which the positive electrode and the negative electrode are stacked and rolled up while placing a separator in between, wherein:wherein a sum (A+B) of a total thickness “A” of a thickness of the positive electrode current collector and a thickness of the positive electrode active material layer, and a total thickness “B” of a thickness of the negative electrode current collector and a thickness of the negative electrode active material layer ranges from 161 μm to 220 μm, both ends inclusive, andwherein a ratio (A/B) of the total thickness “A” of the positive electrode to the total thickness “B” of the negative electrode ranges from 0.65 to 1.9, both ends inclusive.

2. The secondary battery as claimed in claim 1, wherein an open circuit voltage under completely charged state per a single pair of the positive electrode and the negative electrode ranges from 4.25 V to 4.50 V, both ends inclusive.

3. The secondary battery as claimed in claim 1, wherein the electrolyte is a gel-form electrolyte, the gel-form electrolyte includes a copolymer of hexafluoropropylene with polyvinylidene fluoride or with vinylidene fluoride, and an electrolytic solution containing a non-aqueous solvent and an electrolyte salt immersed therein.

4. The secondary battery as claimed in claim 3, wherein the non-aqueous solvent is a carbonate ester compound containing ethylene carbonate and propylene carbonate, and wherein a ratio by weight of the ethylene carbonate to the propylene carbonate ranges from 0.25 to 1.50, both ends inclusive.

5. The secondary battery as claimed in claim 3, wherein the electrolyte salt is a lithium salt comprising LiPF6.

6. The secondary battery as claimed in claim 1, wherein the separator comprises polyethylene (PE) or polypropylene (PP).

7. The secondary battery as claimed in claim 3, wherein the gel-form electrolyte is a layer formed by uniformly coating the electrolytic solution onto the positive electrode and the negative electrode, so as to immerse the electrolytic solution thereinto.