Pole piece, electrochemical device, and electronic device

Abstract

The application discloses a pole piece, an electrochemical device and an electronic device, and belongs to the field of electrochemical energy storage. The pole piece comprises a composite current collector and an active material layer, the composite current collector comprises a polymer layer, and an interface strengthening layer and a metal layer are sequentially arranged on both sides of the polymer layer in a thickness direction of the polymer layer and away from the polymer layer; the active material layer comprises a silicon-containing material; the thickness of the polymer layer is T microns, the mass percentage of the silicon-containing material is C si % based on the mass of the active material layer, and the porosity of the silicon-containing material is P; T, C si , and P satisfy the following conditions: T = 3.6 * C Si / P + 1.5, 5% ≤ C Si ≤ 30%, and 20% ≤ P ≤ 50%. The pole piece disclosed by the application has high compatibility between the composite current collector and the silicon material, and can effectively buffer the silicon expansion.

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