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.

Abstract: The present invention discloses a wireless telemetry device for collecting wheel-rail force signals, comprising: a wireless telemetry module, a power supply module, a signal transmission module and a controller. The wireless telemetry module is installed on a wheel axle of a train; a power supply output induction module is installed on a bogie of the train; a power supply receiving induction coil is installed on the wheel axle and electrically connected with the wireless telemetry module; a signal receiving induction module is installed on the bogie of the train; a signal output induction coil is installed on the wheel axle; the controller is installed on the bogie of the train; and the controller realizes signal connection with the signal receiving induction module. In the present invention, the wireless telemetry module and the controller can realize non-contact power transmission and signal transmission.

Abstract: Provided are an apparatus, process, and roller for forming electrode plate. The apparatus for forming electrode plate includes a first roller and a second roller. An inner cavity of a cylinder of the first roller is provided with a gas outlet structure, the gas outlet structure is connected to a gas supply apparatus, and surface of the cylinder of the first roller is provided with a circumferentially distributed cylinder gas discharge structure. The second roller is disposed opposite the first roller, and a gap is provided between the first roller and the second roller for rolling an electrode material into an electrode film.

Abstract: Embodiments of the present application provide a negative electrode plate, a secondary battery, a battery module, a battery pack and an electrical device. The negative electrode plate may comprise a negative electrode current collector; and a negative electrode active material layer, wherein the negative electrode active material layer may be disposed on at least one surface of the negative electrode current collector, and comprise, based on total weight of the negative electrode active material layer, 90.0% to 98.6% by weight of a negative electrode active material; 1.0%-5.0% by weight of a polymer binder; and 0.2%-4.0% by weight of a toughening fiber.

Abstract: A binder includes a polymer obtained by polymerizing at least a first component, a second component, and a third component. The first component includes a flexible monomer selected from C4-18 alkene. The second component includes a rigid monomer including at least one of an alkene having a rigid group or a polymerized monomer having a strong polar group. The rigid group is selected from C5-20 aryl, C4-8 saturated or unsaturated ring group, and C5-30 heterocyclyl. The third component includes a hydrophilic monomer containing a hydrophilic group selected from carboxyl, hydroxyl, amine, aldehyde, alcohol, amino, and amido.