Flame-retardant pole piece for lithium ion battery as well as preparation method and application of flame-retardant pole piece

The invention relates to a flame-retardant pole piece for a lithium ion battery as well as a preparation method and application of the flame-retardant pole piece, and belongs to the technical field of lithium ion batteries. The technical problems that in the prior art, when a flame retardant is directly added into a battery system, the electrical performance of a battery cell is often deteriorated, and an improved flame retardant is complex in synthesis, uncontrollable in cost, unclear in long-term influence on a battery and the like are solved. The flame-retardant pole piece disclosed by the invention is prepared by rolling a composite piece; the composite sheet is composed of a first isolation layer, a first flame-retardant layer, a foil material, a second flame-retardant layer and a second isolation layer which are arranged in sequence. The first isolation layer and the second isolation layer are made of sodium carboxymethyl cellulose; the first flame-retardant layer and the second flame-retardant layer ar