Abstract: The present application provides a negative electrode plate, a method of preparing the same, a secondary battery, and an electrical device. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer provided on the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material and an additive, the additive includes a shell wall and a cavity located on an inner side of the shell wall, a thickness of the shell wall is denoted as d, a volume of the cavity is denoted as Vh, a volume of the additive is denoted as Vw, and the additive satisfies 20 nm?d?300 nm and 40%?Vh/Vw?90%. The present application can effectively reduce the expansion force of secondary batteries and improve the safety performances of secondary batteries.

Abstract: This application provides a battery and an electrical device, and relates to the field of batteries. The battery includes a plurality of battery cells and a busbar component. The busbar component includes a buffer portion and two connecting portions. The buffer portion is connected between the two connecting portions along a first direction. The two connecting portions are connected to two of the battery cells respectively to implement electrical connection between the two battery cells. Along a second direction, the buffer portion protrudes from the connecting portions toward the battery cells. The second direction is perpendicular to the first direction. The busbar component of the battery includes a buffer portion.

Abstract: The present application provides a battery cell, a battery, and an electrical device, belonging to the field of battery technology. The battery cell includes a positive electrode sheet and an electrolyte solution. A coating mass of a positive electrode active material layer on a single side of the positive electrode sheet is 410 mg/1540.25 mm2 to 550 mg/1540.25 mm2, and a membrane resistance of the positive electrode sheet is ?1?. A conductivity of the electrolyte solution is ?14 mS/cm. The battery cell has thick coated electrode sheets, where the lower membrane resistance of the positive electrode sheet indicates its higher conductivity, which is conducive to reducing solid-state ohmic resistance of the battery cell. The higher conductivity of the electrolyte solution is conducive to reducing liquid-phase ohmic impedance of the battery and alleviating concentration polarization to some extent.

Abstract: A positive electrode material composition includes a positive electrode active material and optionally, an optional positive electrode conductive agent, the positive electrode active material includes a core and a shell on at least a portion of a surface of the core, the core includes lithium phosphate, the shell includes a carbon material, a graphitization degree of the positive electrode active material is denoted as g1, a mass percentage of the positive electrode conductive agent in the positive electrode material composition is denoted as w1, 10%?g1?50%, and 0%?w1?1%.