▎ 摘　　要

NOVELTY - Polymer base material has a base layer (1). The material of the base layer includes a first polymer. The base layer includes a front side and a back side oppositely arranged along the thickness direction. A reinforcement layer (2) covering the front and back of the base layer. The material of the reinforcement layer includes a second polymer (21), a conductive agent (23) and a flame retardant (22). The mass proportion of the flame retardant in the reinforcing layer is 1-60 wt.%. USE - The polymer base material is useful for preparing composite current collector. Can also be used in composite current collector of electrochemical device (all claimed) e.g. lithium-ion battery and lithium polymer battery. ADVANTAGE - The base material has sandwich structure of the reinforcement layer, the base layer, and the reinforcement layer, increase the tensile strength of the base material applied to the current collector, reduce the risk of thermal runaway of the polymer substrate, improves the use safety of the polymer substrate without affecting the mechanical strength of the polymer substrate, and improve the conductivity of the polymer substrate, is capable of not reducing polymer substrate safety performance, mechanical property, thermal stability under the premise of chemical stability and electrical conductivity, reduces the dosage of the flame retardant substrate, and reduces the polymer substrate preparation cost. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a preparation method of polymer base material. DESCRIPTION OF DRAWING(S) - The drawing shows a structure schematic diagram of the polymer base material. 1Base layer 2Reinforcement layer 21Second polymer 22Flame retardant 23Conductive agent