SECONDARY BATTERY AND ELECTRIC APPARATUS CONTAINING SAME
This application provides a secondary battery, including a negative electrode plate, where the negative electrode plate may include: a negative electrode current collector; a first negative electrode film layer disposed on at least one surface of the negative electrode current collector, where the first negative electrode film layer may include a first negative electrode active material and a first conductive polymer, a mass percentage of the first conductive polymer in the first negative electrode film layer is recorded as A, and A≤6%; and a second negative electrode film layer disposed on a surface of the first negative electrode film layer, where the second negative electrode film layer may include a second negative electrode active material and a second conductive polymer, and a mass percentage of the second conductive polymer in the second negative electrode film layer is recorded as B; where the negative electrode plate may satisfy A>B.
1 . A secondary battery, comprising a negative electrode plate, wherein the negative electrode plate comprises:
a negative electrode current collector;
a first negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the first negative electrode film layer comprises a first negative electrode active material and a first conductive polymer, a mass percentage of the first conductive polymer in the first negative electrode film layer is recorded as A, and A≤6%; and
a second negative electrode film layer disposed on a surface of the first negative electrode film layer, wherein the second negative electrode film layer comprises a second negative electrode active material and a second conductive polymer, and a mass percentage of the second conductive polymer in the second negative electrode film layer is recorded as B; wherein
the negative electrode plate satisfies A>B.
2 . The secondary battery according to claim 1 , wherein 1%≤5A≤5%.
3 . The secondary battery according to claim 2 , wherein 1%≤A≤3%.
4 . The secondary battery according to claim 1 , wherein B≤4%
5 . The secondary battery according to claim 4 , wherein 0.5%≤B≤3%.
6 . The secondary battery according to claim 1 , wherein A/B≤10.
7 . The secondary battery according to claim 6 , wherein A/B≤5.
8 . The secondary battery according to claim 1 , wherein the first conductive polymer and the second conductive polymer are independently selected from one or more of polyaniline, polypyrrole, polythiophene and derivatives thereof, poly(3,4-ethylenedioxythiophene), polyacetylene, polyphenylene, and polyphenylacetylene.
9 . The secondary battery according to claim 1 , wherein the first negative electrode active material and the second negative electrode active material both comprise artificial graphite.
10 . The secondary battery according to claim 1 , wherein a median particle size by volume D v 50 of the first negative electrode active material is greater than a median particle size by volume D v 50 of the second negative electrode active material.
11 . The secondary battery according to claim 10 , wherein the median particle size by volume D v 50 of the first negative electrode active material is 6 μm to 15 μm; and/or
the median particle size by volume D v 50 of the second negative electrode active material is 0.5 μm to 8 μm.
12 . The secondary battery according to claim 11 , wherein the median particle size by volume D v 50 of the first negative electrode active material is 8 μm to 12 μm; and/or
the median particle size by volume D v 50 of the second negative electrode active material is 4 μm to 6 μm.
13 . The secondary battery according to claim 1 , wherein a specific surface area (SSA) of the first negative electrode active material is less than a specific surface area (SSA) of the second negative electrode active material.
14 . The secondary battery according to claim 13 , wherein the specific surface area (SSA) of the first negative electrode active material is 0.5 m 2 /g to 2 m 2 /g; and/or
the specific surface area (SSA) of the second negative electrode active material is 1.5 m 2 /g to 5 m 2 /g.
15 . The secondary battery according to claim 1 , wherein an OI value of the first negative electrode active material is greater than an OI value of the second negative electrode active material.
16 . The secondary battery according to claim 15 , wherein the OI value of the first negative electrode active material is 4 to 20; and/or
the OI value of the second negative electrode active material is 0.5 to 10.
17 . The secondary battery according to claim 1 , wherein a thickness of the first negative electrode film layer is recorded as H 1 , a thickness of the second negative electrode film layer is recorded as H 2 , and the secondary battery satisfies 0.5≤H 1 /H 2 ≤3.
18 . The secondary battery according to claim 17 , wherein
20 μm H≤110 μm; and/or
20 μm≤H 2 ≤110 μm.
19 . The negative electrode plate according to claim 9 , wherein the first negative electrode active material and/or the second negative electrode active material further comprise(s) one or more of natural graphite, hard carbon, and silicon-based material.
20 . An electric apparatus, containing the secondary battery according to claim 1 .