Looking back over lithium

Since scientists demonstrated the first rechargeable lithium-ion battery in 1976, the technology has proven its world-changing potential in the electronics industry. But even as applications in electric vehicles and stationary storage record massive growth, the technology has issues to overcome and scientists the world over are hard at work on integrating new materials and pushing more performance out of batteries still based on the concepts illustrated by scientists almost half a century ago.

And looking back over these developments can be valuable in informing the future direction of research. Arumugam Manthiram has been a professor at the University of Texas at Austin for 20 years, and has also worked on lithium-ion technology alongside Nobel Prize-winning scientist John Goodenough. In a review paper published in Nature Communications, Manthiram delves into the history of lithium-ion technology and examines the issues influencing current research into new battery concepts.

“Cost and sustainability are becoming critical as we move forward with large-scale deployment of lithium-ion batteries,” says Manthiram. “Also, there is an appetite to increase the energy density beyond the current level to keep up with the advances in portable electronic devices and enhance the driving range of electric vehicles.”

Big three

The paper outlines three major discoveries that brought about the lithium-ion batteries we see on the market today.

The first demonstration of a rechargeable battery with a lithium-metal anode and titanium sulfide cathode by M. Stanley Whittingham at Exxon in the 1970s provided proof of concept for recent advances in the understanding of intercalation chemistry. This battery was hampered by low voltage and energy density, as well as dendrite growth on the lithium-metal anode – a problem scientists today are still working to solve.

Next Manthiram focuses on work by John Goodenough’s group in the 1980s, which was awarded the 2019 Nobel Prize for Chemistry. This concerns the design of oxide cathodes, which allowed for increased voltage in the battery. Goodenough’s group also divided oxide cathodes into three classes (layered, spinel and polyanion), which remain the only practical cathode types to this day, and serve as the basis for future developments.

Finally, further work by Goodenough’s group in the 1980s, led by visiting researcher Koichi Mizushima, provided the first demonstration of a lithium battery with a carbon anode and lithium cobalt oxide cathode. It represented the first time the technology overcame safety and energy density issues, and was presented as something ready for commercialization.

To the future

But with society placing ever-increasing demands on batteries, these concerns have remained at the core of ongoing research into lithium-ion technology.

“We need to increase the energy density through an increase in the charge-storage capacities of the cathode and anode, an increase in the operating voltage of the cathode, or ideally an increase in both charge-storage capacity and operating voltage,” Manthiram told pv magazine. “Development of new or better electrode materials and electrolytes are needed to accomplish these goals. Novel synthesis and processing approaches along with computational modeling can assist these tasks.”

Manthiram notes that in the near term, he expects to see research focus on layered oxide cathodes with more nickel and less or no cobalt, and also adding silicon to graphite anodes as methods to increase energy density.

Further into the future, there is a wealth of technologies that could ultimately prove their worth. “Lithium-ion batteries will maintain their leading position for energy storage, particularly for electrification of the transportation sector,” says Manthiram. “Moving forward, lithium-sulfur batteries could increase the energy density further with a reduction in cost. Sodium-ion batteries can enhance the sustainability. Ultimately, all-solid-state batteries could offer further increase in energy density with better safety.”