Abstract: An electrode assembly for a lithium-ion secondary battery and a preparation method thereof, and a lithium-ion secondary battery are disclosed. The electrode assembly comprises an electrode and an electrode post, where an electrode tab is extended from the electrode; a welding connection portion is formed by welding between the electrode tab and the electrode post; the welding connection portion has a bulge welding defect; the surface of the welding connection portion is covered with a polymer protective layer, and the thickness of the polymer protective layer is greater than or equal to the thickness of the bulge welding defect; and the bulge welding defect is embedded in the polymer protective layer.

Abstract: A silicon negative electrode comprises a current collector coated with a negative electrode material. The negative electrode material comprises a silicon negative active material and a binder. The binder comprises a first polymer, a second polymer, and a third polymer. The first polymer comprises a fluorine-containing monomer. The second polymer comprises a monomer selected from the group consisting of acrylonitrile, methacrylonitrile, acrylates, methacrylates, and combinations thereof. The third polymer is selected from the group consisting of polyvinylpyrrolidone, polyalkylidene glycol, polyacrylamide, polyethylene glycol, and combinations thereof.

Abstract: In one aspect, a negative plate for a battery comprises a negative current collector coated with a negative active material. The negative current collector comprises a conductive non-woven fabric. In another aspect, a method for preparing a negative plate for a battery comprises coating a negative active material onto a negative current collector. The negative current collector comprises a conductive non-woven fabric. In yet another aspect, a battery comprises a negative plate. The negative plate comprises a negative current collector coated with a negative active material. The negative current collector comprises a conductive non-woven fabric.