▎ 摘　　要

NOVELTY - Flat sodium metal battery comprises an anode piece whose surface is provided with a first micro-through hole that is arranged in an array. A cathode piece is formed with a second micro through hole. An overlapped area of the first and the second micro through hole is not less than5% of the total area of the second micro-through hole of the cathode piece. The anode piece comprises anode active material comprises sodium transition metal oxide, polyanion compound and/or Prussian blue compound. The cathode pole piece comprises a porous current collector at least part of the surface coated with a conductive coating comprises conductive agent comprising conductive carbon black, graphite, carbon fiber, single and multi-wall carbon nano-tube, graphene and/or fullerene and a binder comprising polyvinylidene fluoride, sodium carboxymethyl cellulose, styrene-butadiene rubber, sodium alginate, lithium polyacrylate, sodium polyacrylate, polytetrafluoroethylene, polyimide and/or polyurethane. USE - The flat-plate sodium metal battery is useful in an electrochemical device i.e. lithium ion battery of an electric automobile. ADVANTAGE - The flat-plate sodium metal battery: can form the electrolyte which wets the electric core uniformly; improves the wetting quality and permeability of the electrolyte thus realizes the fast infiltration of the large pole piece and improves the first coulomb efficacy and cycle performance of the electrode core; arranges of the first and the second micro-holes which is conducive to the rapid infiltration of large-size pole pieces; avoids the problem of insufficient infiltration in the central local area due to the capillary effect; has high energy density, multiplying power performance and cycle efficacy; and is economical. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for electrochemical device.