Cell Design and Materials: Li-Ion

Technology Trends INDUSTRIALIZED SEPARATOR TECHNOLOGIES Layer

Separator Type

Material

Advantages

Base Layer

Dry-Process Polyolefin

Polypropylene or Polyethylene

Wet-Process Polyolefin

Coating

EMERGING TECHNOLOGIES What

Why

Strength, Lowest cost

Aramid nanofiber composite coatings

Facilitates safety, higher performance than existing ceramic

Polyethylene

Low thickness, electrolyte wetting, low cost vs non-polyolefin options

Flame retardant separator technology

Enhances safety from reduced risk of fire

Nonwoven Fabric

Nonwoven materials made of synthetic fibers: Polyethylene terephthalate PET, Polyimide PI

Porosity, Electrolyte absorption, thermal stability

Solvent-free and water-based PVDF binders

Provides ability to laminate multiple electrode layers together, dimensional stability, safety

Glass Fiber

Often composed of polyethylene or polypropylene with added fillers or ceramic coatings

Thermal Stability, Ionic Conductivity

PVDF coatings with solvent-free and/or PFAS-free processes

Eliminates of potentially harmful chemicals from process

Ceramic Coatings

Alumina, boehmite, silica

Thermal stability, reduced shrink

High-modulus separator designed to withstand Si swelling stress

Allows higher Si content in anode by withstanding swelling stresses

Adhesive Coatings

Poly(vinylidene difluoride) PVDF, optionally modified PVDFHFP

Adhesion, electrolyte wetting, chemical resistance

Non-woven separators for ESS

Claims improved cycle life, safety, electrolyte wetting

Fiber-Reinforced Coatings

Hybrid coatings combining high-strength fibers (e.g., aramid) with polymer binders.

Strength, thermal stability, reduced shrink

Fully-inorganic separator and electrolyte battery

Enables liquid-free solid-state,adds safety and flammability performance

High-temperature Polymers

Aramids, Polyimides, Polymers of Intrinsic Microporosity PIM

Thermal stability, strength, ion selectivity

Ion selective polymer separators, polymers of intrinsic microporosity PIM

Reduces weight, improves energy density, helps reduce impact of transition metals

Source: Royal Society of Chemistry, Renewable and Sustainable Energy News

Who

Extracted from the PDF; charts and images may read imperfectly.