Polymer Electrolyte Systems for Electrochemical Energy Storage

Polymer electrolyte systems have emerged as a cornerstone technology for next-generation electrochemical energy storage devices, notably lithium-ion and beyond-lithium batteries, as well as supercapacitors and fuel cells. By immobilising conductive species within a polymer matrix, these materials offer improved thermal and mechanical stability alongside enhanced safety by eliminating flammable liquid electrolytes. Ion transport in these systems is governed by the segmental motion of polymer chains, demanding a careful balance between mechanical rigidity—to suppress dendrite formation—and chain flexibility—to facilitate high ionic conductivity. Innovations in molecular architecture, including block copolymers, graft and bottlebrush designs, and single-ion conductors, have delivered tunable ionic pathways, while incorporation of inorganic fillers, ionic liquids and nanostructured domains has further optimised conductivity and interfacial compatibility. Recent trends spotlight additive manufacturing approaches to create bicontinuous nanoscale networks and the design of protogenic channels within crystalline phases that mimic aqueous proton conduction. Collectively, these advances promise robust, high-performance polymer electrolytes capable of supporting greater energy densities, extended cycle life and new chemistries such as magnesium and zinc metal batteries. Future directions centre on molecular engineering to decouple mechanical and transport properties, sustainable bio-derived polymers, and interfacial strategies for integration with high-voltage electrodes.

Research from Nature Portfolio

Recent studies have demonstrated the potential of single-ion block copolymers engineered with crystalline protogenic channels to achieve high-efficiency proton conduction under anhydrous conditions. By precisely tuning dipolar interactions and spatial arrangements of proton donors and acceptors, these materials attain dielectric properties comparable to water and facilitate rapid structural diffusion, delivering proton diffusion coefficients in excess of 2×10⁻⁶ cm² s⁻¹ at 90 °C. This work underscores the value of nanoscale ionic crystallinity in eliminating polarization losses and paves the way for solid-state proton-exchange membranes.

Polymer Electrolyte Systems for Electrochemical Energy Storage publication trend

The graph below shows the total number of articles in polymer electrolyte systems for electrochemical energy storage across all publications each year (not limited to Nature Index journals).

Technical terms

Solid polymer electrolyte (SPE): A polymer matrix containing dissolved salt or ionic species through which ions migrate via the motion of polymer chain segments.

Ionic conductivity: A measure of a material’s ability to transport ions, expressed in siemens per centimetre (S cm⁻¹).

Bottlebrush polymer: A macromolecule with a linear backbone densely grafted with side-chain polymers, creating a brush-like architecture.

Bicontinuous nanostructure: An interpenetrating network of two continuous phases at the nanoscale, used to decouple mechanical and conductive domains.

Protogenic channel: A crystalline pore or pathway designed to facilitate proton hopping and structural diffusion in single-ion conductors.

Polymerisation-induced microphase separation (PIMS): A technique in which phase separation occurs during polymerisation, forming well-defined nanoscale domains without post-processing.

Gel polymer electrolyte (GPE): A polymer network swollen with liquid electrolyte or ionic liquid to combine mechanical integrity with high ionic mobility.

References

1. Highly Conductive Polyoxanorbornene‐Based Polymer Electrolyte for Lithium‐Metal Batteries. Advanced Science (2023).
2. 3D Printed Solid Polymer Electrolytes with Bicontinuous Nanoscopic Domains for Ionic Liquid Conduction and Energy Storage. Small (2023).
3. Inorganic Fillers in Composite Gel Polymer Electrolytes for High-Performance Lithium and Non-Lithium Polymer Batteries. Nanomaterials (2021).
4. Tuning anhydrous proton conduction in single-ion polymers by crystalline ion channels. Nature Communications (2018).