INTERNALLY SERIAL BATTERY AND ELECTRIC APPARATUS

This application provides an internal series battery. The internal series battery includes a series module, a positive current collector, and a negative current collector. The series module includes battery units and intermediate current collectors. The number of the battery units is greater than or equal to 3. Each of the battery units includes a positive active material layer, a solid electrolyte layer, and a negative active material layer that are stacked. Each of the intermediate current collectors is disposed between the corresponding two adjacent battery units, and the two adjacent battery units are connected in series through the intermediate current collector. The positive current collector is located at one end of the series module and is electrically connected to the positive active material layer of the battery unit at the end. The negative current collector is located at the other end of the series module and is electrically connected to the negative active material layer of the battery unit at the end. The battery units include a first battery unit and a second battery unit. An energy density of the first battery unit is the same as an energy density of any one of the battery units at two ends of the series module. An energy density of the second battery unit is different from energy densities of the battery units at the two ends of the series module.