In the quest for safer, high-energy-density lithium metal batteries (LMBs), researchers have long been stymied by the limitations of composite quasi-solid-state electrolytes. These materials, crucial for enabling LMBs, often suffer from discontinuous ion transport, poor interfacial stability, and limited high-voltage endurance. However, a groundbreaking study led by Manxi Wang from the Engineering Research Center of Polymer Green Recycling of Ministry of Education at Fujian Normal University in China, published in the journal *Interdisciplinary Materials* (translated as *Cross-Disciplinary Materials*), offers a promising solution.
Wang and her team have developed a universal in situ growth strategy to construct a metal-organic framework (MOF)/polymer composite electrolyte (ZCPSE) with hierarchically ordered ion-conducting networks. The innovation lies in the ultra-uniform MOF nanoparticles, such as ZIF-8, which are anchored onto polymer nanofibers. This creates abundant nanopores and Lewis acid sites that synergistically enhance lithium-ion (Li⁺) transport and oxidative stability.
“The key here is the 3D continuous MOF/polymer interface,” Wang explains. “It facilitates rapid Li⁺ dissociation and uniform flux distribution, which is crucial for the performance and safety of LMBs.”
The resulting ZCPSE exhibits unprecedented ionic conductivity (0.46 mS cm⁻¹ at 25°C), a wide electrochemical window (5.15 V vs. Li/Li⁺), and exceptional mechanical strength (151.2 MPa, four times higher than pristine polymer membrane). Theoretical simulations reveal that the 3D continuous MOF/polymer interface facilitates rapid Li⁺ dissociation and uniform flux distribution, endowing ZCPSE with a high Li⁺ transference number (0.74) and dendrite-free Li plating/stripping (2000 hours in Li|Li symmetric cells).
Practical applicability is demonstrated in Li|LiFePO₄ cells (stable cycling at 25°C–100°C) and high-voltage Li|LiNi₀.₈Co₀.₁Mn₀.₁O₂ full cells (4.5 V, 100 cycles with 99.2% capacity retention). “This study provides a paradigm for designing MOF-based hybrid electrolytes with simultaneous ionic, mechanical, and interfacial optimization,” Wang notes, highlighting the potential for safe and high-energy LMBs.
The implications for the energy sector are profound. High-energy-density, thermally stable, and mechanically robust electrolytes could revolutionize the design and safety of next-generation batteries. This could accelerate the adoption of electric vehicles and grid storage solutions, addressing critical energy challenges.
As the world continues to seek sustainable and efficient energy solutions, Wang’s research offers a beacon of hope. By pushing the boundaries of materials science, she and her team are paving the way for safer, more efficient, and high-performance lithium metal batteries. The study, published in *Cross-Disciplinary Materials*, marks a significant step forward in the field, promising to shape future developments in energy storage technologies.