Improving Lithium-Ion Batteries: the Magnesium Solution

Climate Break

Lithium Ion Batteries

Lithium ion batteries are a popular type of rechargeable battery, used in a variety of devices from laptops and cell phones to hybrid and electric vehicles. Lithium ion batteries have grown in use due to their light weight, high energy density, and ability to recharge. While these batteries are used to store electricity and, therefore, as an element of alternative to fossil fuels, the process to mine and obtain lithium has harmful effects on the environment.

Lithium is a soft, light metal found in rocks and subsurface fluids called brines. The mining of battery materials and manufacturing the batteries can generate significant amounts of greenhouse gas emissions. The disposal of these batteries is also a concern, as the battery cells can release toxins such as heavy metals into soil and groundwater if not properly disposed of. In these cases, lithium ion batteries have also been found to cause fires, which is especially dangerous if misplaced in a landfill. There is a growing effort to recycle these batteries due to the environmental issues and demand for batteries, but that faces obstacles as well.

A New Alternative

Due to the concerns around the safety, cost and supply of materials for lithium-ion batteries, the industry is in search of more sustainable elements to use for batteries, such as manganese. Researchers at the U.S. Department of Energy’s Argonne National Laboratory are developing lithium-ion cathode technology that has sustainable increased use of manganese.

When a battery charges, lithium ions flow from the cathode to the anode, a process that reverses when the battery is discharged. Researchers have already created a nickel-manganese-cobalt (NMC) cathode material that is rich in lithium that has the potential to have increased storage capacity over conventional materials. The Argonne National Laboratory is working on a version of NMC technology that boosts the lithium and manganese content to improve the batteries energy density and safety while decreasing costs.

A battery with a manganese-rich cathode is less expensive and safer than one with high nickel concentrations, but not without caveats. Increasing the manganese and lithium content can decrease the cathode's stability, impacting its performance overtime.

Future of Batteries

The U.S. Department of Energy has made it a priority to find more sustainable materials for electric vehicle batteries. Other strategies include decreasing the amount of cobalt by using higher percentages of nickel, but this also poses challenges. Nickel is more abundant than cobalt but less than a fifth of the current supply is suitable for battery use. In reality, there is less nickel than expected and increased use could cause a spike in prices.

At the Lawrence Berkeley National Laboratory, a consortium of scientists is developing the commercialization of a new family of battery cathode materials called DRX, or disordered rock salt. DRX could provide batteries with higher energy densities than conventional lithium-ion batteries that contained metals in short supply, like nickel and cobalt. The consortium is focused on making DRX cathodes out of more affordable and abundant metals, like manganese and titanium.

About our Guest

Dr. Jason Croy is a Materials Scientist at Argonne National Laboratory whose work focuses on the design, synthesis, and characterization of high-energy lithium-ion electrode materials. Prior to his work at the Argonne National Laboratory, Croy was a musician and toured with his rock band for nearly ten years before attending college. He taught himself physics before enrolling in college, then going on to earn his Ph.D. in Physics from University of Central Florida. Croy is an internationally recognized expert on lithium- and manganese-rich cathode materials and has published numerous articles on the atomic-scale mechanisms governing the performance of lithium-ion electrodes.

For a transcript of this episode, please visit https://climatebreak.org/improving-lithium-ion-batteries-the-magnesium-solution/