Imagine a world where electric vehicles travel longer distances without the burden of expensive materials. A breakthrough from MIT researchers has brought us closer to that vision. On October 7, 2024, a team led by Professor Ju Li unveiled a new class of cathode material for lithium-ion batteries, known as disordered rock salt-polyanionic spinel (DRXPS). This innovative material combines the strengths of two existing cathode types, delivering high energy density and remarkable cycling stability.
As Yimeng Huang, a postdoctoral researcher involved in the study, explains, “There is typically a trade-off in cathode materials between energy density and cycling stability... with this work, we aim to push the envelope by designing new cathode chemistries.” By integrating rock salt with polyanionic olivine, DRXPS achieves a balance that could revolutionize battery technology.
One of the most significant advantages of DRXPS lies in its primary component: manganese. Unlike nickel and cobalt, which are both costly and scarce, manganese is abundant and much cheaper—at least five times less expensive than nickel and about 30 times less than cobalt. Professor Li emphasizes, “Having that material be much more earth-abundant is a tremendous advantage.” This affordability is crucial as the world shifts towards renewable energy sources.
With the pressing need for efficient energy storage solutions for electric vehicles and renewable energy systems, the implications of this discovery are vast. DRXPS could help address the intermittency issues of wind and solar power by storing excess energy for use during low-generation periods. “If we want to have true electrification of energy generation, transportation, and more, we need earth-abundant batteries,” asserts Li.
The study also tackles a major challenge in using disordered rock salt cathodes—the mobility of oxygen, which can lead to material degradation. By introducing phosphorus, the researchers effectively stabilize the oxygen, enhancing the longevity and performance of the batteries. “The main innovation here... is that Yimeng added just the right amount of phosphorus, formed so-called polyanions with its neighboring oxygen atoms,” explains Li.
While the potential of DRXPS is immense, further research is necessary to optimize its production and scalability. Huang notes that the current synthesis method yields non-uniform materials that are not easily scalable. The team is exploring new techniques to improve the material's morphology and reduce the amount of conductive carbon needed, which could further enhance the battery's energy density.
As the world races towards a sustainable future, the development of affordable, efficient battery technologies like DRXPS could play a pivotal role in the clean energy transition. With ongoing research, this innovative cathode material may soon power everything from electric cars to renewable energy systems, making it a cornerstone of our energy future.