Sustainable Cellulosic Separator Technologies for Lithium-Ion Batteries

Sustainable cellulosic separators offer a renewable alternative to conventional polyolefin membranes in lithium-ion batteries by combining high thermal stability, intrinsic flame retardance and superior electrolyte affinity with the potential for low-cost, large-scale production. Derived from wood pulp, bacterial cellulose or agro-industrial by-products, these materials can be engineered at the nanoscale to achieve tailored pore structures that facilitate rapid ionic transport while preventing dendritic growth. Surface functionalisation or composite formation with inorganic fillers, conductive polymers and flame-retardant moieties further enhances mechanical strength, electrolyte wettability and electrochemical stability. Such advancements mitigate safety risks associated with thermal runaway and separator meltdown, address sustainability imperatives through biodegradability and lower carbon footprints, and open pathways to circular-economy approaches by valorising cellulose waste streams. Ongoing research focuses on optimising porosity and thickness, controlling surface chemistry for selective ion sieving and integrating multifunctional layers that combine redox activity, mechanical reinforcement and thermal protection. The global imperative for safer, greener energy storage has driven interdisciplinary efforts to translate these laboratory advances into robust separators for high-energy density, fast-charging and long-lifetime battery applications.

Research from Nature Portfolio

Research has demonstrated a novel approach to generate straight nanopores in cellulose acetate films by incorporating a nickel(II) nitrate complex followed by isostatic water pressure treatment. This method leverages the plasticisation effect of the metal salt to weaken polymer chains selectively, allowing uniform pore formation without high-temperature processes. Molecular simulations confirm favourable interactions between the modified matrix and common liquid electrolytes. The resulting separators exhibit enhanced electrolyte uptake, improved ionic mobility and reliable performance in coin-cell tests, highlighting a scalable route to high-flux, cellulosic gel separators with robust thermomechanical properties.

Sustainable Cellulosic Separator Technologies for Lithium-Ion Batteries publication trend

The graph below shows the total number of articles in sustainable cellulosic separator technologies for lithium-ion batteries across all publications each year (not limited to Nature Index journals).

Technical terms

Separator: A microporous membrane that electrically isolates cathode and anode while permitting ion transport through its pores.

Porosity: The volume fraction of void space in a separator, determining electrolyte uptake and ionic conductivity.

Electrolyte affinity (wettability): The ability of a separator to absorb and retain liquid electrolyte, ensuring uniform ion pathways.

Ionic conductivity: A measure of the ease with which ions migrate through the separator under an electric field.

Dendrite formation: The growth of metallic filaments (typically lithium) that can penetrate separators and cause short circuits.

References

1. Cellulose Separators for Rechargeable Batteries with High Safety: Advantages, Strategies, and Perspectives. Advanced Functional Materials (2024).
2. Facile control of nanoporosity in Cellulose Acetate using Nickel(II) nitrate additive and water pressure treatment for highly efficient battery gel separators. Scientific Reports (2017).
3. Sustainable lithium-ion battery separators based on cellulose and soy protein membranes. Electrochimica Acta (2023).
4. Electrospun Sandwich-like Structure of PVDF-HFP/Cellulose/PVDF-HFP Membrane for Lithium-Ion Batteries. Molecules (2023).