Internal series battery and electrical device
This application provides an internal series battery, including a series module including three or more battery units, each including a positive active material layer, a solid electrolyte layer and a negative active material layer stacked, and intermediate current collectors, each disposed between the corresponding two adjacent battery units connected in series therethrough; a positive current collector located at one end of the series module and electrically connected to the positive active material layer of the battery unit at the end; and a negative current collector located at the other end of the series module and 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 that have an energy density the same as and different from any one of the battery units at the two ends of the series module respectively.
1 . An internal series battery, comprising:
a series module, comprising battery units and intermediate current collectors; a number of the battery units being greater than or equal to 3, each of the battery units comprising a positive active material layer, a solid electrolyte layer, and a negative active material layer that are stacked; each of the intermediate current collectors being corresponding to and disposed between two adjacent battery units, and the two adjacent battery units being connected in series through the intermediate current collector;
a positive current collector, located at one end of the series module and electrically connected to the positive active material layer of the battery unit at one end of two ends of the series module opposite to each other; and
a negative current collector, located at the other end of the series module and electrically connected to the negative active material layer of the battery unit at the other end of the two ends of the series module,
wherein the battery units comprise at least two first battery units and at least one second battery unit; the at least two first battery units comprise two battery units respectively at the two ends of the series module, the at least one second battery unit is inside the series module between the two first battery units;
wherein an energy density of each first battery unit is greater than an energy density of each second battery unit; each first battery unit independently comprises a lithium-ion battery positive active material, each second battery unit independently comprises a sodium-ion battery positive active material; a ratio of a number of the at least one second battery unit to a total number of the battery units is 1/3 to 2/3.
2 . The internal series battery according to claim 1 , wherein the ratio of the number of the at least one second battery unit to the total number of the battery units is 1/3 to 1/2.
3 . The internal series battery according to claim 1 , wherein the solid electrolyte layer of the at least one second battery unit comprises a high-safety additive;
the high-safety additive comprises at least one of phosphate ester and fluorocarbonate;
the phosphate ester comprises at least one of trimethyl phosphate and triethyl phosphate; and
the fluorocarbonate comprises at least one of methyl difluoroacetate and ethyl difluoroacetate.
4 . An electrical device, comprising the internal series battery according to claim 1 .
5 . The internal series battery according to claim 1 , wherein the at least one second battery unit comprises a plurality of second battery units in series connection.
6 . The internal series battery according to claim 1 , wherein the at least one second battery unit comprises a plurality of second battery units in series connection.
7 . An internal series battery, comprising:
a series module, comprising battery units and intermediate current collectors; a number of the battery units being greater than or equal to 3, each of the battery units comprising a positive active material layer, a solid electrolyte layer, and a negative active material layer that are stacked; each of the intermediate current collectors being corresponding to and disposed between two adjacent battery units, and the two adjacent battery units being connected in series through the intermediate current collector;
a positive current collector, located at one end of the series module and electrically connected to the positive active material layer of the battery unit at one end of two ends of the series module opposite to each other; and
a negative current collector, located at the other end of the series module and electrically connected to the negative active material layer of the battery unit at the other end of the two ends of the series module,
wherein the battery units comprise at least two first battery units and at least one second battery unit; the at least two first battery units comprise two battery units respectively at the two ends of the series module, the at least one second battery unit is inside the series module between the two first battery units;
wherein an energy density of each first battery unit is less than an energy density of each second battery unit; each first battery unit independently comprises a sodium-ion battery positive active material, each second battery unit independently comprises a lithium-ion battery positive active material; a ratio of a number of the at least one second battery unit to a total number of the battery units is 1/3 to 2/3.
8 . The internal series battery according to claim 7 , wherein the ratio of the number of the at least one second battery unit to the total number of the battery units is 1/3 to 1/2.
9 . The internal series battery according to claim 7 , wherein the solid electrolyte layer of the at least one second battery unit comprises a high-safety additive;
the high-safety additive comprises at least one of phosphate ester and fluorocarbonate;
the phosphate ester comprises at least one of trimethyl phosphate and triethyl phosphate; and
the fluorocarbonate comprises at least one of methyl difluoroacetate and ethyl difluoroacetate.