Team develops battery component designed to make lithium metal batteries safer and more powerful
Novel organic-inorganic composite electrolyte
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An asymmetric quasi-solid-state composite electrolyte was constructed by evaporation-induced self-assembly of 1D molecular brushes and 0D hairy ceramic nanoparticles, followed by in situ polymerization. The resulting ultrathin quasi-solid-state composite electrolyte delivers a high ionic conductivity and a lithium-ion transference number of 0.67, and enables lithium iron phosphate cells to operate for 200 cycles with 94% capacity retention at 0.5 C.
view moreCredit: Energy Materials and Devices, Tsinghua University Press
A research team has developed a new type of battery component that results in safer and higher-capacity batteries. It can improve lithium metal batteries’ safety, reliability, and electrochemical performance. Their work provides a feasible molecular engineering strategy for developing safe, high-performance lithium metal batteries.
This research was published in the journal Energy Materials and Devices on June 24, 2026.
“Simply put, we aimed to make a safer, thinner, and faster-charging lithium metal battery free of internal short-circuit risks,” said Yin Cui, Sun Yat-sen University. The development of electric vehicles and smart grids has led to a growing demand for batteries that are safer and have greater energy density. Traditional lithium-ion batteries cannot meet these needs. Lithium metal batteries can store far more energy than conventional lithium-ion batteries, but they are dangerous because lithium metal tends to form dendrites that can pierce the separator and trigger internal short circuits.
In recent years, scientists have explored solid-state composite electrolytes. These hold promise as electrolyte systems for solid-state lithium-metal batteries. However, their application in lithium-metal batteries has been restricted because of challenges, such as poor interfacial compatibility between different functional components, low ionic conductivity at room temperature, and difficulty in completely inhibiting the growth of lithium dendrites.
Quasi-solid-state composite electrolytes have distinctive multilayer architectures that allow function customization based on the cathode and anode requirements. Yet the current quasi-solid-state composite electrolytes lack the qualities needed to attract and guide the lithium ions. These electrolytes also work poorly in colder temperatures. There are still significant challenges in the current development of asymmetric quasi-solid-state composite electrolytes.
The research team set out to design a novel organic-inorganic composite electrolyte for longer-lasting, safer batteries. Their core goal was to develop an asymmetric quasi-solid-state composite electrolyte through evaporation-induced self-assembly of molecular brushes and hairy nanoparticles, followed by in situ cationic ring-opening polymerization. “This asymmetric electrolyte can not only achieve intimate interfacial contact with the cathode, but also effectively suppress lithium dendrites growth on the anode side, significantly improving the overall safety, reliability, and electrochemical performance of lithium metal batteries,” said Cui.
The team notes that constructing an asymmetric double-sided electrolyte represents an extremely practical route to developing safe and high-performance lithium metal batteries. Their ultrathin electrolyte (19 μm) has two different functional sides: a rigid ceramic-rich side blocking lithium dendrites physically and a flexible polymer composite side ensuring tight contact with the cathode. These polymer chains on the surface of nanomaterials can evenly distribute lithium ions and simultaneously speed up lithium-ion transfer.
“This design delivers three standout real-world advantages: great ionic conductivity, a high lithium-ion transference number, and stable long-cycle battery life,” said Cui. By integrating 1D molecular brushes and 0D hairy ceramic nanoparticles, the team created a continuous 3D ion transport network. The new material they created helps the charged particles move much more efficiently. This molecular synergy is the core innovation behind their excellent electrochemical data.
The team’s study showed that designing unique asymmetric quasi-solid-state composite electrolytes via molecular engineering is a promising research direction to fundamentally promote lithium-ion conduction and stabilize the lithium anode. This method provides a viable strategy for the practical application of high-performance solid-state lithium-metal batteries.
Looking ahead, the team’s next step is to scale up this fabrication process and test the electrolyte in larger‑format batteries, not just coin cells. They also aim to further optimize the composition to boost ionic conductivity and verify long‑term stability under practical operating conditions, especially during fast charging. “Our ultimate goal is to enable practical, safe lithium metal batteries that outperform today’s lithium‑ion systems in electric vehicles, drones, and portable electronics, especially in cold climates where current batteries struggle. In the longer term, we hope this molecular self‑assembly approach can be adapted to other solid‑state battery chemistries, such as sodium or potassium, broadening the impact beyond lithium,” said Cui.
The research team includes Shenghao Lin, Yin Cui, Guofang Yu, Dongtian Miao, and Dingcai Wu from the School of Chemistry, Sun Yat-sen University, Guangzhou, China, and Ruliang Liu from the School of Chemistry and Materials Science, Guangdong University of Education, Guangzhou, China.
This research is funded by the National Key Research and Development Program of China; the National Natural Science Foundation of China; the Guangdong Major Project of Basic and Applied Basic Research; the Natural Science Foundation of Guangdong; the Fundamental Research Funds for the Central Universities, Sun Yat-sen University; the Science and Technology Program of Guangzhou; and the Guangdong Basic Research Center of Excellence for Functional Molecular Engineering.
DOI Link:
https://doi.org/10.26599/EMD.2026.9370095
Journal
Energy Materials and Devices
Article Title
Asymmetric quasi-solid-state composite electrolytes via self-assembly of molecular brushes and hairy nanoparticles for dendrite-free lithium metal batteries
Activating interfaces for faster lithium transport in solid-state batteries
A dual-function interphase activator helps lithium ions move across garnet-polymer interfaces, offering a practical route toward safer high-energy lithium-metal batteries
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Activating interfaces for faster lithium transport in solid-state batteries
view moreCredit: ©Science Bulletin
Solid-state lithium-metal batteries are considered one of the most promising technologies for next-generation energy storage because they can potentially deliver high energy density while improving battery safety. Yet their practical development is still limited by a fundamental challenge: lithium ions must move efficiently across solid-solid interfaces, where contact, chemistry, and transport are often poorly matched.
This challenge is particularly important in polymer-ceramic composite solid electrolytes. Garnet-type LLZTO is known for its high lithium-ion conductivity and good chemical stability, while PVDF-based polymers provide flexibility and processability. However, combining the two materials does not automatically create a fast ion-transport network. LLZTO surfaces are easily covered by lithium carbonate and lithium hydroxide after air exposure, and these surface species hinder lithium-ion movement. Meanwhile, semicrystalline PVDF itself has limited lithium-ion conductivity at room temperature. These issues make the ceramic-polymer interface a major bottleneck for solid-state battery performance.
To address this problem, a research team led by Professor Renjie Chen at Beijing Institute of Technology developed an interphase activator strategy for PVDF-LLZTO composite solid electrolytes. Instead of treating ceramic surface modification and polymer ion transport as two separate problems, the strategy couples both processes through one additive.
In this study, SbF3 was used as a representative interphase activator. It performs two connected functions. First, it converts the native lithium carbonate and lithium hydroxide species on the LLZTO surface into a reconstructed Sb2O3/LiF-rich interphase. This reconstructed interphase provides a more favorable local environment for lithium-ion transfer at the garnet surface. Second, together with ion-conducting cellulose, SbF3 regulates the coordination environment in the PVDF-based polymer phase, reduces polymer chain ordering, and promotes faster lithium-ion coordination and decoordination.
Through this dual-function design, the optimized electrolyte, named FPIT-11, forms a continuous lithium-ion percolation pathway across the LLZTO bulk, the reconstructed interphase, and the polymer coating. Experimental characterizations and theoretical calculations show that the Sb2O3/LiF heterogeneous interface lowers the lithium-ion migration barrier, while the polymer phase becomes more disordered and more favorable for lithium-ion transport.
The optimized FPIT-11 electrolyte delivers an ionic conductivity of 6.7 × 10−4 S cm−1, a lithium-ion transfer number of 0.84, and a lithium-ion conductivity of 5.6 × 10−4 S cm−1 at 30 ℃. It also shows a wide electrochemical stability window of 5.25 V versus Li/Li+, indicating potential compatibility with high-voltage cathodes.
The electrolyte also demonstrates strong stability against lithium metal. Symmetric lithium cells using FPIT-11 cycle stably for nearly 2400 hours at 0.2 mA cm−2 and reach a critical current density of 3 mA cm−2 under 3 MPa pressure. Further interfacial analysis reveals the formation of a lithium nitride-rich multiphase inorganic interphase on the lithium-metal surface, which helps support stable lithium plating and stripping.
Full-cell tests further demonstrate the practical potential of this strategy. LiFePO4, NCM523, and lithium-rich manganese-based cathode cells using FPIT-11 show stable cycling performance at 30 ℃. In particular, NCM523-based solid-state cells maintain stable cycling for 770 cycles, while pouch-cell tests also show good operational stability and safety.
This work provides a new design principle for garnet-polymer composite solid electrolytes. By integrating ceramic surface reconstruction with polymer-phase transport activation, the interphase activator strategy offers a practical path toward solid-state lithium-metal batteries with improved ion transport, interfacial stability, and cycling performance.
Journal
Science Bulletin
