FLAT-PLATE SODIUM METAL BATTERY AND ELECTROCHEMICAL DEVICE

1 . A flat-plate type sodium metal battery, comprising a positive electrode plate and a negative electrode plate, the positive electrode plate provided with a first micro-through-hole arranged in an array on at least part of the surface thereof, the negative electrode plate provided with a second micro-through-hole arranged in an array on at least part of the surface thereof,

wherein the first micro-through-hole and the second micro-through-hole have an overlapping area of ≥5% of the total area of the second micro-through-hole of the negative electrode plate.

2 . The battery according to claim 1 , wherein:

(1) the first micro-through-hole has an aperture of from 1 μm to 100 μm;

(2) the first micro-through-hole is from 1 mm to 10 mm away from its adjacent first micro-through-hole; and/or

(3) a ratio of an area of the first micro-through-hole to an area of the positive electrode plate is less than 1%.

3 . The battery according to claim 1 , wherein:

(1) the second micro-through-hole has an aperture of from 1 μm to 20 μm;

(2) the second micro-through-hole is from 1 mm to 5 mm away from its adjacent second micro-through-hole; and/or

(3) a ratio of an area of the second micro-through-hole to an area of the negative electrode plate is less than 0.1%.

4 . The battery according to claim 1 , wherein the positive electrode plate comprises a positive active material, and the positive active material is at least one of sodium transition metal oxide, polyanionic compound, and Prussian blue compound.

5 . The battery according to claim 1 , wherein the negative electrode plate comprises a porous current collector and a conductive coating coated on at least part of the surface of the porous current collector.

6 . The battery according to claim 5 , wherein:

(1) the conductive coating has a thickness of from 1 μm to 5 μm;

(2) a ratio of an area of the conductive coating to a pore area of the porous current collector is ≥20%;

(3) the conductive coating comprises a conductive agent and a binder, and the conductive agent is present in the conductive coating in a mass percentage content of from 10% to 80%;

(4) the conductive coating comprises a conductive agent and a binder, and the conductive agent comprises at least one of conductive carbon black, graphite, carbon fiber, single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene, and fullerenes; and/or

(5) the conductive coating comprises a conductive agent and a binder, and the binder is at least one of polyvinylidene fluoride, sodium carboxymethyl battery cellulose, styrene-butadiene rubber, sodium alginate, lithium polyacrylate, sodium polyacrylate, polytetrafluoroethylene, polyimide, and polyurethane.

7 . The battery according to claim 1 , wherein the battery further comprises a separator wherein,

(1) the separator comprises at least one of polypropylene microporous films, polyethylene microporous films, polyimide microporous films, and polyethylene terephthalate microporous films; and/or

(2) the separator has a thickness of from 5 μm to 15 μm.

8 . The battery according to claim 1 , wherein the positive electrode plates and negative electrode plates are prepared by laser drilling, mechanical punching or a combination thereof.

9 . The battery according to claim 1 , wherein the battery has a battery cell in a flat-plate structure, the battery cell has a length and width of from 400 mm to 1600 mm, the battery cell has a thickness of from 10 mm to 40 mm, a ratio of the length and the width of the battery cell is (1.1˜3.9):1, and a ratio of the length to the thickness of the battery cell is (10˜150):1.

10 . An electrochemical device, comprising the battery according to claim 1 .