BATTERY CELL, BATTERY MODULE, BATTERY PACK, AND ELECTRICAL APPARATUS
A battery cell, a battery module, a battery pack, and an electrical apparatus are provided. The battery cell includes an intermediate portion and side portions located on two sides of the intermediate portion in a thickness direction, the intermediate portion comprising m battery cell sub-units and the side portions comprising n battery cell sub-units, where m+n is an integer greater than or equal to 3. Each of the battery cell sub-units comprises a positive electrode sheet, a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet, and each of the m battery cell sub-units has a dry battery cell nail penetration short-circuit resistance greater than that of each of the n battery cell sub-units.
1 . A battery cell, comprising an intermediate portion and side portions located on two sides of the intermediate portion in a thickness direction, the intermediate portion comprising m battery cell sub-units and the side portions comprising n battery cell sub-units, m+n being an integer greater than or equal to 3, wherein
each of the battery cell sub-units comprises a positive electrode sheet, a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet, and
each of the m battery cell sub-units has a dry battery cell nail penetration short-circuit resistance greater than that of each of then battery cell sub-units.
2 . The battery cell of claim 1 , wherein
the intermediate portion has a thickness accounting for 20% to 40% of a total thickness of the battery cell.
3 . The battery cell of claim 1 , wherein
the positive electrode sheet comprises a positive electrode current collector, the positive electrode current collector comprising a support layer and a metal layer, and
the support layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness greater than that of the support layer of the positive electrode current collector of each of then battery cell sub-units.
4 . The battery cell of claim 3 , wherein
the metal layer of the positive electrode current collector of each of the m battery cell sub-units has a resistivity greater than that of the metal layer of the positive electrode current collector of each of the n battery cell sub-units.
5 . The battery cell of claim 4 , wherein the resistivity of the metal layer of the positive electrode current collector of each of the m battery cell sub-units is 1.05 to 1.5 times the resistivity of the metal layer of the positive electrode current collector of each of then battery cell sub-units.
6 . The battery cell of claim 3 , wherein
the metal layer of the positive electrode current collector of each of the m battery cell sub-units has a thickness smaller than that of the metal layer of the positive electrode current collector of each of then battery cell sub-units.
7 . The battery cell of claim 6 , wherein the thickness of the metal layer of the positive electrode current collector of each of them battery cell sub-units is 60% to 90% of the thickness of the metal layer of the positive electrode current collector of each of then battery cell sub-units.
8 . The battery cell of claim 1 , wherein
the positive electrode sheet of each of them battery cell sub-units has a coating weight smaller than that of the positive electrode sheet of each of then battery cell sub-units.
9 . The battery cell of claim 8 , wherein the coating weight of the positive electrode sheet of each of the m battery cell sub-units is 70% to 90% of the coating weight of the positive electrode sheet of each of the n battery cell sub-units; and/or
the negative electrode sheet of each of the m battery cell sub-units has a coating weight smaller than that of the negative electrode sheet of each of the n battery cell sub-units.
10 . The battery cell of claim 8 , wherein the coating weight of the negative electrode sheet of each of the m battery cell sub-units is 70% to 90% of the coating weight of the negative electrode sheet of each of then battery cell sub-units.
11 . The battery cell of claim 1 , wherein
a binder in the positive electrode sheet of each of the m battery cell sub-units has a content greater than that of a binder in the positive electrode sheet of each of the n battery cell sub-units.
12 . The battery cell of claim 11 , wherein the content of the binder in the positive electrode sheet of each of the m battery cell sub-units is 3% by weight to 4% by weight, and the content of the binder in the positive electrode sheet of each of the n battery cell sub-units is 1% by weight to 2% by weight; and/or
a binder in the negative electrode sheet of each of the m battery cell sub-units has a content greater than that of a binder in the negative electrode sheet of each of the n battery cell sub-units.
13 . The battery cell of claim 12 , wherein the content of the binder in the negative electrode sheet of each of the m battery cell sub-units is 3% by weight to 4% by weight, and the content of the binder in the negative electrode sheet of each of the n battery cell sub-units is 1% by weight to 2% by weight.
14 . The battery cell of claim 1 , wherein
the positive electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the positive electrode sheet of each of then battery cell sub-units.
15 . The battery cell of claim 14 , wherein the compaction density of the positive electrode sheet of each of the m battery cell sub-units is 80% to 98% of the compaction density of the positive electrode sheet of each of the n battery cell sub-units; and/or
the negative electrode sheet of each of the m battery cell sub-units has a compaction density smaller than that of the negative electrode sheet of each of the n battery cell sub-units.
16 . The battery cell of claim 14 , wherein the compaction density of the negative electrode sheet of each of the m battery cell sub-units is 80% to 98% of the compaction density of the negative electrode sheet of each of the n battery cell sub-units.
17 . The battery cell of claim 1 , wherein
the separator of each of the m battery cell sub-units has a thickness greater than that of the separator of each of then battery cell sub-units.
18 . The battery cell of claim 17 , wherein the thickness of the separator of each of them battery cell sub-units is 10 to 13 μm, and the thickness of the separator of each of the n battery cell sub-units is 7 to 9 μm.
19 . A battery pack, comprising the battery cell of claim 1 .
20 . An electrical apparatus, comprising the battery pack of claim 24 , wherein the battery pack is used as a power source or an energy storage unit of the electrical apparatus.