▎ 摘　　要

NOVELTY - The cathode pole piece has a cathode material layer comprising silicon-based particles and graphite particles. The silicon-based particles comprise silicon elements and carbon elements. A particle diameter of the silicon-based particles is greater than 3 mum. A silicon content of a surface area is less than a silicon content in an inner area. A surface of the silicon-based particles is carbon material i.e. amorphous carbon, carbon nano-tube, carbon nanoparticle, vapor deposition carbon fiber and/or graphene. USE - Cathode pole piece for electrochemical device i.e. lithium-ion secondary battery of electronic device i.e. electric energy storage, mobile electronic device, electric automobile and aerospace equipment. ADVANTAGE - A surface stress of the cathode pole piece is reduced, so as to improve interface stability of the silicon-based particles and the electrolyte, which effectively improves circulation performance and expansion deformation of the electrochemical device. The cathode material layer maintains high gram capacity, reduces contact of electrolyte and reduces generation of solid electrolyte interface film (SEI). The electronic device has good cycle performance, anti-expansion performance, rate capability and volumetric energy density. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) electrochemical device; and (2) electronic device. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of silicon-based particle of cathode pole piece for electrochemical device i.e. lithium-ion secondary battery of electronic device i.e. electric energy storage, mobile electronic device, electric automobile and aerospace equipment. Surface area (30) Internal region (40)