SECONDARY BATTERY
A secondary battery includes a positive electrode plate and a negative electrode plate. The negative electrode plate includes a negative electrode current collector, a negative electrode active material layer provided on at least one surface of the negative electrode current collector, and an insulation layer and a reaction layer sequentially provided on a surface of the negative electrode active material layer on a side opposite to the negative electrode current collector. The reaction layer includes at least one of graphite, silicon, silicon oxide, silicon suboxide, tin oxide, copper oxide, or zinc oxide. A capacity per unit area, A1 (mAh/cm 2 ), of a positive electrode active material layer in the positive electrode plate and a capacity per unit area, B1 (mAh/cm 2 ), of the negative electrode active material layer in the negative electrode plate satisfy B1/A1<1.
1 . A secondary battery comprising:
a positive electrode plate; and
a negative electrode plate comprising:
a negative electrode current collector;
a negative electrode active material layer provided on at least one surface of the negative electrode current collector; and
an insulation layer and a reaction layer sequentially provided on a surface of the negative electrode active material layer on a side opposite to the negative electrode current collector, the reaction layer comprising at least one of graphite, silicon, silicon oxide, silicon suboxide, tin oxide, copper oxide, or zinc oxide;
wherein a capacity per unit area, A1 (mAh/cm 2 ), of a positive electrode active material layer in the positive electrode plate and a capacity per unit area, B1 (mAh/cm 2 ), of the negative electrode active material layer in the negative electrode plate satisfy B1/A1<1.
2 . The secondary battery according to claim 1 , wherein A1 and B1 satisfy
0.3≤B1/A1<1.
3 . The secondary battery according to claim 1 , wherein:
the insulation layer comprises at least one of aluminum oxide, boehmite, zirconium oxide, titanium oxide, magnesium oxide, cobalt oxide, nickel oxide, gallium oxide, germanium oxide, yttrium oxide, strontium oxide, barium oxide, or molybdenum oxide.
4 . The secondary battery according to claim 1 , wherein:
the battery satisfies that:
(
A
1
-
B
1
m
1
)
ρ
×
1000
-
15
≤
d
≤
(
A
1
-
B
1
m
1
)
ρ
×
1000
+
20
d: a thickness of the reaction layer, in μm;
m1: a gram capacity of the reaction layer, in mAh/g;
ρ: a density of the reaction layer, in g/cm 3 .
5 . The secondary battery according to claim 1 , wherein a gram capacity m1 of the reaction layer satisfies m1≥150 mAh/g.
6 . The secondary battery according to claim 1 , wherein m1 satisfies
1000 mAh/g≤m1≤2500 mAh/g.
7 . The secondary battery according to claim 1 , wherein a density p of the reaction layer satisfies 0.2 g/cm 3 ≤ρ≤3 g/cm 3 .
8 . The secondary battery according to claim 1 , wherein ρ satisfies 1 g/cm 3 ≤ρ≤2 g/cm 3 .
9 . The secondary battery according to claim 1 , wherein:
a thickness of the reaction layer is 1 μm-30 μm; and/or
a thickness of the insulation layer is 1 μm-10 μm.
10 . The secondary battery according to claim 1 , wherein:
a thickness of the reaction layer is 2 μm-30 μm; and/or
a thickness of the insulation layer is 2 μm-4 μm.
11 . The secondary battery according to claim 1 , wherein:
a Young's Modulus of the insulation layer is greater than or equal to 6 GPa.
12 . The secondary battery according to claim 1 , wherein:
a Young's Modulus of the insulation layer is in a range of 6 GPa −30 GPa.
13 . The secondary battery according to claim 1 , wherein:
a particle size of a material in the reaction layer is 0.1 μm-4 μm; and/or
a particle size of a material in the insulation layer is 0.1 μm-10 μm.
14 . The secondary battery according to claim 1 , wherein:
a particle size of a material in the reaction layer is 0.1 μm-4 μm, optionally 0.1 μm-0.8 μm; and/or
a particle size of a material in the insulation layer is 0.1 μm-10 μm, optionally 0.1 μm-4 μm.
15 . The secondary battery according to claim 1 , wherein:
B1 is 0.3 mAh/cm 2 -7 mAh/cm 2 ; optionally, 1 mAh/cm 2 -5 mAh/cm 2 .
16 . The secondary battery according to claim 1 , wherein:
B1 is 1 mAh/cm 2 -5 mAh/cm 2 .
17 . The secondary battery according to claim 1 , wherein:
A1 is 1 mAh/cm 2 -7 mAh/cm 2 .
18 . The secondary battery according to claim 1 , wherein:
A1 is 2 mAh/cm 2 -5 mAh/cm 2 .
19 . A battery pack comprising a secondary battery comprising:
a positive electrode plate;
a negative electrode plate comprising:
a negative electrode current collector;
a negative electrode active material layer provided on at least one surface of the negative electrode current collector;
an insulation layer and a reaction layer sequentially provided on a surface of the negative electrode active material layer on a side opposite to the negative electrode current collector, the reaction layer comprising at least one of graphite, silicon, silicon oxide, silicon suboxide, tin oxide, copper oxide, or zinc oxide;
wherein a capacity per unit area, A1 (mAh/cm 2 ), of a positive electrode active material layer in the positive electrode plate and a capacity per unit area, B1 (mAh/cm 2 ), of the negative electrode active material layer in the negative electrode plate satisfy B1/A1<1.
20 . A power consuming device comprising a secondary battery comprising:
a positive electrode plate;
a negative electrode plate comprising:
a negative electrode current collector;
a negative electrode active material layer provided on at least one surface of the negative electrode current collector;
an insulation layer and a reaction layer sequentially provided on a surface of the negative electrode active material layer on a side opposite to the negative electrode current collector, the reaction layer comprising at least one of graphite, silicon, silicon oxide, silicon suboxide, tin oxide, copper oxide, or zinc oxide;
wherein a capacity per unit area, A1 (mAh/cm 2 ), of a positive electrode active material layer in the positive electrode plate and a capacity per unit area, B1 (mAh/cm 2 ), of the negative electrode active material layer in the negative electrode plate satisfy B1/A1<1.