A consortium of battery scientists, led by Lawrence Berkeley National Laboratory (Berkeley Lab), will accelerate the commercialization of a new family of battery cathode materials called DRX or “disordered rock salt.” DRX cathodes could provide batteries with higher energy density than conventional lithium-ion battery cathodes made of nickel and cobalt, two metals that are in critically short supply.

In a rock salt structure, cations (positively charged ions) and anions (negatively charged ions) are arranged in a specific pattern. In the case of DRX, this structure can become disordered—i.e., the arrangement of atoms in the crystal structure is not highly ordered or regular. This disorder can enhance the material’s electrochemical properties by improving insertion and removal of lithium ions during charge and discharge cycles.

The US Department of Energy (DOE) has made it a priority to find ways to reduce or eliminate the use of cobalt in batteries. In support of that initiative, the DRX Consortium is focused on making DRX cathodes made of manganese or titanium, which are both more abundant and cheaper than nickel or cobalt. Lithium batteries made with DRX cathodes could safeguard the automobile industry and therefore consumers from higher prices spurred by supply constraints.

DRX cathodes can be made with almost any transition metal instead of nickel and cobalt. That versatility is key if we want to replace gasoline vehicles with electric vehicles.

—principal investigator Gerbrand Ceder

Ceder is co-leading the DRX Consortium with fellow battery scientist Guoying Chen at Berkeley Lab.

Formed last fall, the DRX Consortium—which includes a team of approximately 50 scientists from Berkeley Lab, SLAC National Accelerator Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, Oak Ridge National Laboratory, and the University of California at Santa Barbara—was awarded $20 million from the Vehicle Technologies Office in DOE’s Office of Energy Efficiency and Renewable Energy.

The funding—allocated in $5 million yearly increments through 2025—will allow the consortium to develop DRX battery cathodes that could perform just as well if not better than the NMC (nickel-manganese-cobalt) cathodes used in today’s lithium-ion batteries.

DRX offers more sustainable, more abundant, and cheaper mineral sources for battery cathodes. The lithium-ion battery is a really good energy storage technology, but to stay relevant, it will need to grow toward higher production of multiple terawatt hours per year. Without DRX, lithium-ion batteries would require enormous amounts of nickel and cobalt if we stay with current technologies.

—Gerbrand Ceder

DRX could be the go-to material for battery cathodes. We already have the advantage of cost and resources. Now all we have to do is improve performance.

—Guoying Chen

DRX is still a very young technology—Ceder and his team developed DRX less than 10 years ago, in 2014, as a response to a rapidly growing lithium-ion battery industry. New battery technologies typically take 20 to 30 years to mature. But DRX is on an unusually fast track toward commercialization.

Ceder and Chen demonstrated DRX’s potential during a four-year program called the “Deep Dive,” which was also funded by the DOE Vehicle Technologies Office. That program ended in 2022, and the consortium formed soon after with the goal of demonstrating commercial-ready DRX cathodes in less than 5 years.

The United States aims to make half of all new cars sold in 2030 zero-emissions vehicles, including battery electric, plug-in hybrid electric, or fuel cell electric vehicles. In California, all new cars must be zero-emission vehicles beginning in 2035.

To achieve this ambitious goal, Ceder and Chen formed the DRX Consortium, enlisting top battery scientists from across the country and national lab system to help.

• Researchers at the Department of Energy’s National Energy Research Scientific Computing Center (NERSC) will help the team narrow down the best combination of manganese and titanium through computer modeling.

• Researchers from Oak Ridge National Laboratory and Argonne National Laboratory will work on chemical synthesis and scale up the materials for industry.

• New DRX-compatible electrolytes will be developed at Pacific Northwest National Laboratory.

• Researchers from Berkeley Lab’s Molecular Foundry, SLAC National Accelerator Laboratory, and UC Santa Barbara will assist with materials characterization.

A pioneer in computational materials discovery, Ceder and his team discovered DRX through computer model experiments, many of which were performed at NERSC.

Vince Battaglia and his team at Berkeley Lab will test out Ceder’s DRX cathode designs by fabricating dozens of DRX coin-cell batteries with various formulations of titanium or manganese. The idea is to improve the material’s electronic conductivity, which is crucial to ensuring that a DRX lithium-ion battery not only has high energy density but also a high cycle life.

The Molecular Foundry and NERSC are DOE Office of Science user facilities at Berkeley Lab.

Resources

• Urban, A., Lee, J., Ceder, G. (2014). “The Configurational Space of Rocksalt-Type Oxides for High-Capacity Lithium Battery Electrodes.” Adv. Energy Mater., 4: 1400478. doi: 10.1002/aenm.201400478

• Lun, Z., Ouyang, B., Kwon, DH. et al. (2021) “Cation-disordered rocksalt-type high-entropy cathodes for Li-ion batteries.” Nat. Mater. 20, 214–221 doi: 10.1038/s41563-020-00816-0

• Huang, L., Zhong, P., Ha, Y., Cai, Z., Byeon, Y.-W., Huang, T.-Y., Sun, Y., Xie, F., Hau, H.-M., Kim, H., Balasubramanian, M., McCloskey, B. D., Yang, W., Ceder, G. (2023) “Optimizing Li-Excess Cation-Disordered Rocksalt Cathode Design Through Partial Li Deficiency.” Adv. Energy Mater. 13, 2202345 doi: 10.1002/aenm.202202345

• Patil, S., Darbar, D., Self, E. C., Malkowski, T., Wu, V. C., Giovine, R., Szymanski, N. J., McAuliffe, R. D., Jiang, B., Keum, J. K., Koirala, K. P., Ouyang, B., Page, K., Wang, C., Ceder, G., Clément, R. J., Nanda, J. (2023) “Alternate Synthesis Method for High-Performance Manganese Rich Cation Disordered Rocksalt Cathodes.” Adv. Energy Mater. 13, 2203207. doi: 10.1002/aenm.202203207