Current collector and preparation method therefor, secondary battery, battery module, battery pack, and power consuming device
View Patent ↗A current collector may comprise a strength enhancement layer and a current collecting layer, wherein the current collecting layer may be stacked and bonded with the strength enhancement layer, and the current collecting layer may comprise a foam metal portion and a solid metal portion.
1 . A current collector, comprising:
a strength enhancement layer; and
a current collecting layer stacked and bonded with the strength enhancement layer, the current collecting layer comprising a foam metal portion and a solid metal portion side by side on a surface of the strength enhancement layer,
wherein the solid metal portion is provided at one or both ends of the strength enhancement layer in a width direction.
2 . The current collector according to claim 1 , wherein the solid metal portion extends in a length direction of the current collecting layer.
3 . The current collector according to claim 1 , wherein the solid metal portion comprises a plurality of solid metal portions, with the foam metal portion being provided between two adjacent solid metal portions among the plurality of solid metal portions.
4 . The current collector according to claim 1 , wherein
the strength enhancement layer is a metal layer having a sheet structure; or
the strength enhancement layer is of a mesh structure.
5 . The current collector according to claim 4 , wherein the strength enhancement layer is provided with a through hole.
6 . The current collector according to claim 1 , wherein the current collecting layer comprises two current collecting layers, the two current collecting layers are respectively provided on two sides of the strength enhancement layer, and the strength enhancement layer and the two current collecting layers are provided side by side in a thickness direction of the current collector, the strength enhancement layer being located between the two current collecting layers.
7 . The current collector according to claim 1 , wherein the foam metal portion has a porosity of 20% to 95%.
8 . The current collector according to claim 1 , wherein the foam metal portion comprises a pore channel extending from a side away from the strength enhancement layer to a side close to the strength enhancement layer, the pore channel being tortuous.
9 . The current collector according to claim 8 , wherein the pore channel has a tortuosity t of 1.21-1.33, t=1+ln(1/ε 2 ), ε representing the porosity.
10 . The current collector according to claim 1 , wherein
the strength enhancement layer has a thickness of 4-12 μm; and/or
the current collecting layer has a thickness of 20-400 μm.
11 . The current collector according to claim 1 , wherein
the foam metal portion is made of copper, and the solid metal portion is made of one of a copper-zinc alloy, a copper-aluminum alloy, a copper-manganese alloy and a copper-iron alloy; or
the foam metal portion is made of nickel, and the solid metal portion is made of a nickel-manganese alloy; or
the foam metal portion is made of titanium, and the solid metal portion is made of one of a titanium-scandium alloy, a titanium-copper alloy and a platinum-titanium-copper alloy; or
the foam metal portion is made of gold, and the solid metal portion is made of a gold-silver alloy.
12 . A preparation method for a current collector, the method comprising:
a bonding step comprising stacking an alloy foil for forming a current collecting layer with a strength enhancement layer, and bonding the alloy foil and the strength enhancement layer; and
a foam forming step comprising attaching an anti-corrosion material layer locally on the alloy foil to form an intermediate body to be subjected to foam forming, and placing the intermediate body in a corrosive solution to remove one or more elements constituting the alloy foil from a portion of the alloy foil that is not attached with the anti-corrosion material layer such that the alloy foil forms a foam metal portion, with a portion of the alloy foil that is attached with the anti-corrosion material layer forming a solid metal portion side by side with the foam metal portion on a surface of the strength enhancement layer,
wherein the solid metal portion is provided at one or both ends of the strength enhancement layer in a width direction.
13 . The preparation method according to claim 12 , wherein the corrosive solution includes at least one of a dilute hydrochloric acid solution, an ammonium sulfate solution, an electrolytic solution obtained by mixing H 2 SO 4 and MnSO 4 , an acetic acid solution, a phosphoric acid solution, and a sulfuric acid solution.
14 . The preparation method according to claim 12 , wherein the alloy foil for forming the current collecting layer is bonded to the strength enhancement layer by rolling.
15 . A secondary battery, comprising the current collector according to claim 1 .
16 . A battery module, comprising the secondary battery according to claim 15 .
17 . A battery pack, comprising the battery module according to claim 6 .
18 . A power consuming device, comprising the battery pack according to claim 17 .