Negative current collector, negative electrode plate, electrochemical apparatus, battery module, battery pack, and device

An electrochemical apparatus, comprising a positive electrode plate, a negative electrode plate, a separator separating the positive electrode plate from the negative electrode plate, and an electrolyte, wherein the negative electrode plate comprises:

• a negative current collector;
• and
• a negative electrode active material layer disposed on the negative current collector, wherein the negative current collector comprises:
• a support layer, wherein the support layer has at least two sublayers stacked in a thickness direction, the at least two sublayers comprise different polymer materials;
• a metal conductive layer disposed on at least one of two opposite surfaces of the support layer in the thickness direction of the support layer;
• and
• an upper protective layer comprising:
• a first upper protective layer disposed on a surface of the metal conductive layer facing away from the support layer, the first upper protective layer comprising metal;
• and
• a second upper protective layer disposed on a surface of the first upper protective layer facing away from the support layer, the second upper protective layer comprising metal oxide,
• wherein:
• a density of the support layer is less than a density of the metal conductive layer;
• the density of the metal conductive layer is 8.0 g/cm3 to 8.96 g/cm3;
• a thickness D1 of the metal conductive layer is 300 nm≤D1≤2 μm;
• a thickness Da of the upper protective layer is 100 nm<Da≤200 nm;
• and
• when a tensile strain of the negative current collector is 2.5%, a sheet resistance growth rate T of the metal conductive layer is T≤5%.

A device, comprising an electrochemical apparatus, wherein the electrochemical apparatus serves as a power supply of the device and the electrochemical apparatus further comprises a positive electrode plate, a negative electrode plate, a separator separating the positive electrode plate from the negative electrode plate, and an electrolyte, wherein the negative electrode plate comprises:

• a negative current collector;
• and
• a negative electrode active material layer disposed on the negative current collector, wherein the negative current collector comprises:
• a support layer, wherein the support layer has at least two sublayers stacked in a thickness direction, the at least two sublayers comprise different polymer materials;
• a metal conductive layer disposed on at least one of two opposite surfaces of the support layer in the thickness direction of the support layer;
• and
• an upper protective layer comprising:
• a first upper protective layer disposed on a surface of the metal conductive layer facing away from the support layer, the first upper protective layer comprising metal;
• and
• a second upper protective layer disposed on a surface of the first upper protective layer facing away from the support layer, the second upper protective layer comprising metal oxide,
• wherein:
• a density of the support layer is less than a density of the metal conductive layer;
• the density of the metal conductive layer is 8.0 g/cm3 to 8.96 g/cm3;
• a thickness D1 of the metal conductive layer is 300 nm≤D1≤2 μm;
• a thickness Da of the upper protective layer is 100 nm<Da≤200 nm;
• and
• when a tensile strain of the negative current collector is 2.5%, a sheet resistance growth rate T of the metal conductive layer is T≤5%.