Massachusetts Institute of Technology (MIT) scientists have found a potential breakthrough cathode material that might be the future of battery technology.

They have developed a new class of cathode using rock salt – a breakthrough material for low-cost, high-energy lithium-ion batteries, powering smartphones, renewable energy storage, and electric vehicles.

The study, led by Ju Li, the Tokyo Electric Power Company Professor in Nuclear Engineering and Professor of Materials Science and Engineering, reveals a new class of partially disordered rock salt cathode, integrated with polyanions — called disordered rock salt-polyanionic spinel, or DRXPS, that delivers high energy density at high voltages with significantly improved cycling stability.

“There is typically a trade-off in cathode materials between energy density and cycling stability … and with this work, we aim to push the envelope by designing new cathode chemistries,” said Yimeng Huang, a postdoc in the Department of Nuclear Science and Engineering.

The material has a high energy density and good cycling stability as it integrates two significant types of cathode materials: rock salt and polyanionic olivine. It is composed of magnesium, which is abundant and available at lower prices.

The study also addresses the issue of oxygen mobility. Oxygen becomes mobile when the cathode is charged at high voltage, leading to reactions with the electrolyte and degradation of the material. To address these issues, Huang added phosphorus. It acts like glue, holding the oxygen in place and preventing degradation.

“The main innovation here, and the theory behind the design, is that Yimeng added just the right amount of phosphorus, formed so-called polyanions with its neighboring oxygen atoms, into a cation-deficient rock salt structure that can pin them down,” Li explains.

Charging batteries to higher voltages is crucial as it allows simpler systems to manage the energy they store and provide more stability.

Huang adds that efforts are being made to explore new ways to fabricate the material, particularly for morphology and scalability considerations.

Researchers at Korea Advanced Institute of Science and Technology (KAIST) have developed a high-energy, high-power hybrid sodium-ion battery that could be a viable alternative to lithium-ion batteries.

Led by Jeung Ku Kang, the team of researchers found a way to enhance sodium-ion hybrid energy storage systems through an innovative hybrid energy storage system that integrates anode and cathode materials.

Earlier this year, researchers at Stanford University made progress on an emerging technology that uses liquid organic hydrogen carriers to essentially create a ‘liquid battery’ for storing renewable energy from wind and solar power.