A group of Clemson University chemists, led by Professor Sourav Saha, has developed new dual-conductive materials that simultaneously transport lithium ions and electrons, a unique combination that could improve the performance, safety and longevity of rechargeable lithium-ion batteries.
Practically all portable electronics and electric cars run on lithium-ion batteries, in which tiny lithium ions shuttle back and forth between the anode and cathode as the battery charges and discharges.
But most charge-conducting materials only transport either lithium ions or electrons, not both.
Metal–organic frameworks (MOFs), a relatively new class of porous metal–ligand coordination polymers with open channels and cavities, have unique potential to transport both ions and electrons simultaneously when specific design criteria are met. Thanks to their tunable structures and properties that enable diverse functions, ranging from carbon dioxide capture to lithium-ion storage, MOFs have attracted significant attention over the past two and a half decades, culminating in the 2025 Chemistry Nobel Prize awarded to three pioneers of the field.
The Clemson researchers have developed a hybrid material by combining lithium-ion-conducting MOFs with electrically conductive multiwalled carbon nanotubes, yielding a core-shell heterostructure with nanotube cores surrounded by MOF layers.
Saha’s framework features ytterbium nodes connected by a large organic ligand, hexahydroxy hexaazatrinaphthalene, forming hexagonal layers that can store lithium ions, while electrons can flow along the stacked layers. As a result, it exhibits dual electronic–ionic conductivity. The electronic conductivity of the hybrid MOF–nanotube composite is further boosted by the even more conductive nanotube cores.
“This composite design gives us the best of both worlds. The MOF offers excellent ion transport, and the carbon nanotubes ensure that electrons can move rapidly,” Saha said. “Usually, you get one or the other. Ours does both.”
It is a rare MOF-based dual-conducting material and puts Clemson at the forefront of the field.
The discovery was recently published in the American Chemical Society journal ACS Nano in an article titled, “Dual Electronic and Li Ion Conducting Ytterbium-Hexaazatrinaphthalene Metal-Organic Framework and Its Carbon Nanotube Composites.” In addition to Saha, other researchers involved in this project include graduate student Mohd Ansari, postdoc Ashok Yadav and Applied Computational Lecturer Jorge Barroso. The group has recently relocated to Clemson’s new state-of-the-art Advanced Materials Innovation Complex building.
Saha expressed optimism that their dual conductive MOF and composite materials can be employed as lithium-ion battery electrodes—a possibility they are exploring in collaboration with Clemson Physics Professor Apparao Rao. Their initial studies already show great promise, with these materials exhibiting excellent battery performances.
“Dr. Saha and his team have combined two versatile materials, metal-organic frameworks and carbon nanotubes, to create a new material with promise for making improved lithium-ion batteries,” said Stephen Creager, an Associate Dean and Professor of Chemistry in the College of Science. “His work tackles thedifficult materials chemistry problem of making a material that rapidly transports both ions and electrons, which all battery materials must do. I look forward to seeing this work evolve to improve the rechargeable batteries we use every day in portable electronics, electric cars and other areas.”
