Polyimide coated separators, porous polyimide coatings, lithium batteries, and related methods

Abstract

The instant disclosure or invention is preferably directed to a polyimide coated membrane, separator membrane, or separator for a lithium battery such as a high energy or high voltage rechargeable lithium battery and the corresponding battery. The separator preferably includes a porous or microporous polyimide coating or layer on at least one side of a polymeric microporous layer, membrane or film. The polyimide coating or layer may include other polymers, additives, fillers, or the like. The polyimide coating may be adapted, for example, to provide oxidation resistance, to block dendrite growth, to add dimensional and/or mechanical stability, to reduce shrinkage, to add high temperature performance (HTMI function), to prevent electronic shorting at temperatures above 200 deg C., and/or the like. The microporous polymeric base layer may be adapted, at least, to hold liquid, gel, or polymer electrolyte, to conduct ions, and/or to block ionic flow between the anode and the cathode in the event of thermal runaway (shutdown function). The polyimide coated separator may be adapted, for example, to keep the electrodes apart at high temperatures, to provide oxidation resistance, to block dendrite growth, to add dimensional stability, to reduce shrinkage, to add high temperature performance (HTMI function), to prevent electronic shorting at temperatures above 200 deg C., to increase puncture strength, and/or to block ionic flow between the anode and the cathode in the event of thermal runaway (shutdown function). Although secondary lithium battery usage may be preferred, the instant polyimide coated membrane may be used in a battery, cell, primary battery, capacitor, fuel cell, textile, filter, and/or composite, and/or as a layer or component in other applications, devices, and/or the like.