Abstract: This application relates to an electrode plate structure. With a ratio CB1 of a surface loading of a second cathode material layer to a surface loading of a first anode material layer controlled to be 1:(1.01-1.3) and a ratio CB2 of a surface loading of a first cathode material layer to a surface loading of a second anode material layer controlled to be 1:(1.03-1.4), the surface loadings of the first anode material layer and second anode material layer are slightly higher than the surface loadings of the corresponding second cathode material layer and first cathode material layer, so that during cycling, especially at a high rate, the first anode material layer and the second anode material layer can provide sufficient lithiation capacity, avoiding lithium precipitation on the anode. This application also implements a differential design for the material layers on two sides of the electrode plates.

Abstract: A film preparation apparatus includes a single-screw machine and an extrusion die. The single-screw machine is configured for conveying and extruding an active material mixture, and the extrusion die is connected with a discharge end of the single-screw machine and configured for extruding out an active material film. A screw of the single-screw machine includes a compression section, an axial length of the compression section is L1, an axial length of the screw is L, and 0.45?L1/L?0.65.

Abstract: An electrode plate manufacturing device and an electrode plate manufacturing method are provided. The electrode plate manufacturing device includes an extrusion mechanism, a film forming mechanism and a combination mechanism. The extrusion mechanism is used to extrude out the active material slurry to form a blank. The film forming mechanism is provided downstream of the extrusion mechanism, and the film forming mechanism is used to thin the blank to form a film. The combination mechanism is provided downstream of the film forming mechanism, and the combination mechanism is used to combine the film and a substrate to form an electrode plate. The electrode plate manufacturing device extrudes, through the extrusion mechanism, the active material slurry out to form a blank, so that the powder and particles in the active material slurry may be mixed evenly. The blank is formed into a film through the film forming mechanism.

Abstract: A pole piece manufacturing device is described. The pole piece manufacturing device includes a membrane forming mechanism, a composite mechanism, a detection mechanism and an adjustment mechanism. The membrane forming mechanism is configured to form an active substance into a membrane. The composite mechanism is configured to composite the membrane and a substrate into a pole piece. The detection mechanism is is configured to detect a thickness or a weight per unit area of the membrane. The adjustment mechanism is configured to adjust the membrane forming mechanism according to detection results of the detection mechanism, so as to control the thickness or the weight per unit area of the membrane within a preset range. The membrane is detected by providing the detection mechanism. When the membrane does not meet the design requirements, the membrane forming mechanism is adjusted timely through the adjustment mechanism to make it meet the design requirements.

Abstract: Provided are a secondary battery including an electrode sheet, the electrode sheet including: a current collector and an active material layer; the active material layer is provided on at least one surface of the current collector; the active material layer is divided into a first region and a second region in its thickness direction; the first region is located in a direction close to the surface of the current collector, the thickness of the first region accounts for ½ of the thickness of the active material layer, the binder content in the first region is denoted as A; the second region is located in a direction away from the surface of the current collector, the thickness of the second region accounts for ½ of the thickness of the active material layer, and the binder content in the second region is denoted as B; the electrode sheet satisfies: 1<B/A?1.04.

Abstract: A secondary battery is disclosed. The secondary battery includes a first binder and a second binder, the first binder includes at least one of polyvinylidene fluoride, rubber, epoxy resin, polyurethane, and acrylate, and the second binder includes at least one of polytetrafluoroethylene, polyimide, polypropylene, polyethylene, ethylene vinyl acetate copolymer, and styrene-ethylene-butylene-styrene block copolymer.

Abstract: A drying apparatus for drying a material belt includes at least one material-belt turning mechanism, used for changing a travel direction of the material belt, and including a first passing roller, a turning roller, and a second passing roller sequentially arranged in the travel direction of the material belt. The turning roller is configured to move in a first direction relative to the first passing roller and the second passing roller to adjust a wrap angle of the material belt on the turning roller, the first direction perpendicular to an axial direction of the turning roller.