Metal-Organic Frameworks in Solid-State Electrolytes

Metal-organic frameworks (MOFs) have emerged as highly tunable platforms for the design of solid-state electrolytes in advanced metal-ion batteries. Defined by their crystalline architectures of metal nodes linked by organic ligands, MOFs offer well-ordered pore networks that can accommodate and transport charge-carrying ions. The regular channels and large surface areas facilitate tailored solvation environments and rapid ion conduction, while the rigid framework enhances mechanical stability and suppresses dendrite formation. Recent efforts have focused on modifying pore chemistry, introducing functional groups, and incorporating guest molecules or polymers to optimise ionic conductivity, transference numbers and electrochemical stability windows. These advances have led to quasi-solid and frameworked electrolytes that combine the safety and durability of solids with the favourable transport properties of liquids. Practical implementations have been demonstrated in lithium-metal, sodium and magnesium systems, showing extended cycling life, high rate capability and operation under elevated temperatures. Remaining challenges include achieving conductivity on par with liquid electrolytes at ambient conditions, ensuring interfacial compatibility with electrodes, and developing scalable synthesis routes. Nevertheless, the burgeoning body of work underscores the global significance of MOF-based solid electrolytes for next-generation energy storage, promising safer, higher-energy-density batteries for portable electronics, electric vehicles and grid integration.

Research from Nature Portfolio

A stable quasi-solid electrolyte based on nanoconfined solvents within a 6.5 Å MOF channel has been shown to exhibit nonflammable behaviour, a broad voltage window (≈5.4 V vs Li/Li⁺), and respectable lithium-ion conductivities. When deployed in lithium-metal pouch cells with high-loading NCM-811 cathodes, this electrolyte yields a dendrite-free lithium surface and an interphase-free cathode, achieving over 89 % capacity retention after 300 cycles at 90 °C. Such work illustrates how sub-nanometre confinement within MOF pores can decouple liquid-like ion dynamics from bulk volatility, offering a route to ultrastable, high-voltage solid-state batteries under demanding conditions.

Metal-Organic Frameworks in Solid-State Electrolytes publication trend

The graph below shows the total number of articles in metal-organic frameworks in solid-state electrolytes across all publications each year (not limited to Nature Index journals).

Technical terms

Metal-Organic Framework (MOF): A crystalline assembly of metal ions or clusters bridged by organic ligands, forming porous networks.

Solid-State Electrolyte (SSE): A solid material that facilitates ionic conduction between battery electrodes without liquid solvents.

Ionic Conductivity: The measure of an electrolyte’s ability to transport ions, expressed in siemens per centimetre (S cm⁻¹).

Transference Number: The fraction of total ionic current carried by a specific ion species, indicating transport selectivity.

Electrochemical Stability Window: The voltage range over which an electrolyte remains chemically and electrochemically inert.

References

1. Metal- and covalent-organic frameworks as solid-state electrolytes for metal-ion batteries. Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences (2019).
2. Frameworked electrolytes: Ionic transport behavior and high mobility for solid state batteries. InfoMat (2023).
3. A stable quasi-solid electrolyte improves the safe operation of highly efficient lithium-metal pouch cells in harsh environments. Nature Communications (2022).
4. Ionic Conduction Mechanism and Design of Metal–Organic Framework Based Quasi-Solid-State Electrolytes. Journal of the American Chemical Society (2022).
5. Super Mg2+ Conductivity around 10–3 S cm–1 Observed in a Porous Metal–Organic Framework. Journal of the American Chemical Society (2022).