Patent ID: 11908996
Assignee: LG ENERGY SOLUTION, LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A lithium secondary battery comprising:
a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte solution,
wherein a patterned gel polymer electrolyte layer is included on one surface or both surfaces of at least one structure of the positive electrode or the negative electrode,
wherein the patterned gel polymer electrolyte layer comprises uncoated portions and a plurality of line-type coating portions which are spaced apart from each other and arranged in parallel, and
wherein the line-type coating portions are formed in an oblique direction in direction to an edge of the at least one structure,
wherein the gel polymer electrolyte has a thickness of 0.1 μm to 1 μm, and
wherein an area of the coating portions of the patterned gel polymer electrolyte layer is in a range of 40% to 90% of a total area of the at least one structure of the positive electrode or the negative electrode,
wherein a width of one of lines constituting the coating portion:a width of the uncoated portion between the lines constituting the coating portion is in a range of 1:1 to 10:1,
wherein the width of one of lines constituting the coating portion is in a range of 14% to 90% based on a thickness of the negative electrode,
where in the patterned gel polymer electrolyte layer is formed by:
a) preparing a composition for forming a pattern in which a polymerizable polymer is dissolved in an organic solvent, wherein the polymerizable polymer is at least one selected from the group consisting of polyvinylidene difluoride-chlorotrifluoroethylene copolymer (PVDF-CTFE) and cyanoethyl polyvinyl alcohol (CE-PVA), and wherein the organic solvent is N-methyl-2-pyrrolidone (NMP) or acetone,
b) directly coating the composition on a surface of the at least one structure of the positive electrode or the negative electrode via a micro-gravure method and drying the composition to form a patterned solid polymer electrolyte layer,
c) accommodating an electrode assembly, which includes the at least one structure of the positive electrode or the negative electrode having the solid polymer electrolyte layer formed thereon, in a battery case, and
d) injecting a non-aqueous electrolyte solution to form a patterned gel polymer electrolyte layer.