Negative current collector, negative electrode plate, electrochemical device, and apparatus
View Patent ↗The present disclosure provides a negative current collector ( 10 ), a negative electrode plate ( 20 ), an electrochemical device, and an apparatus. The negative current collector ( 10 ) includes a support layer, and a conductive layer ( 102 ) disposed on at least one of two opposite surfaces of the support layer ( 101 ) in a thickness direction of the support layer; wherein the support layer ( 101 ) has a smaller density than the conductive layer ( 102 ); the conductive layer ( 102 ) has a thickness D 1 satisfying 300 nm≤D 1 ≤2 μm, preferably 500 nm≤D 1 ≤1.5 μm; and when the negative current collector ( 10 ) has a tensile strain of 1.5%, the conductive layer ( 102 ) has a sheet resistance growth rate T satisfying T≤5%.
1. A negative current collector, comprising:
a support layer; and
a conductive layer disposed on at least one of two opposite surfaces of the support layer in a thickness direction of the support layer,
wherein
the support layer has a smaller density than the conductive layer,
the conductive layer has a thickness D 1 satisfying 300 nm≤D 1 ≤2 μm, and
when the negative current collector has a tensile strain of 1.5%, the conductive layer has a sheet resistance growth rate T satisfying T≤2.5%;
the conductive layer comprises copper, or copper alloy; and
the support layer comprises polyethylene terephthalate,
wherein the support layer has a thickness D 2 satisfying 2 μm≤D 2 ≤10 μm.
2. The negative current collector according to claim 1 , wherein the conductive layer has a volume resistivity in a range of 1.3×10 −8 Ω·m to 1.3×10 −7 Ω·m.
3. The negative current collector according to claim 1 , further comprising a protective layer, wherein the protective layer is disposed between the conductive layer and the support layer; and/or the protective layer is disposed on the surface of the conductive layer facing away from the support layer.
4. The negative current collector according to claim 3 , wherein the protective layer comprises one or more of a metallic material or a metal oxide material.
5. The negative current collector according to claim 3 , wherein the protective layer has a thickness D 3 satisfying 1 nm≤D 3 ≤200 nm and D 3 ≤0.1D 1 .
6. The negative current collector according to claim 1 , wherein the thickness D 2 satisfies 2 μm≤D2≤6 μm.
7. The negative current collector according to claim 1 , wherein the support layer further comprises an additive, and the additive comprises one or more of a metallic material and an inorganic non-metallic material.
8. The negative current collector according to claim 1 , wherein the support layer has an elongation at break greater than or equal to that of the conductive layer; and/or,
the support layer has a Young's modulus E satisfying E≥4 GPa.
9. The negative current collector according to claim 1 , wherein the conductive layer is a vapor deposited layer or an electroplated layer.
10. A negative electrode plate, comprising:
a negative current collector; and
a negative active material layer disposed on the negative current collector
wherein the negative current collector is the negative current collector according to claim 1 .
11. An electrochemical device, comprising:
a positive electrode plate;
a negative electrode plate; and
an electrolyte,
wherein the negative electrode plate is the negative electrode plate according to claim 10 .
12. An apparatus, comprising the electrochemical device according to claim 11 .
13. The negative current collector according to claim 1 wherein the conductive layer has a thickness D 1 satisfying 500 nm≤D 1 ≤1.5 μm.
14. The negative current collector according to claim 1 , wherein the conductive layer has a volume resistivity in a range of 1.3×10 −8 Ω·m to 3.3×10 −8 Ω·m.
15. The negative current collector according to claim 3 , wherein the protective layer comprises one or more of nickel, chromium, nickel-based alloy, copper-based alloy, aluminum oxide, cobalt oxide, chromium oxide, or nickel oxide.