Manganese is a plentiful and inexpensive resource. A new technique could position it as a viable substitute for nickel and cobalt in batteries.
Rechargeable lithium-ion batteries are increasingly being used in various applications such as smartphones, laptops, electric vehicles, and energy storage systems. However, the availability of nickel and cobalt, which are typically found in the cathodes of these batteries, is limited. Recent research spearheaded by the Lawrence Berkeley National Laboratory, part of the Department of Energy, reveals that manganese, the fifth most abundant metal in the Earth’s crust, could serve as a feasible low-cost and safe alternative.
Researchers have demonstrated that manganese can be effectively integrated into new cathode materials known as disordered rock salts (DRX). Prior studies indicated that to achieve optimal performance, DRX materials needed to be finely ground into nanosized particles through a labor-intensive process. However, the latest findings reveal that manganese-based cathodes can perform remarkably well with much larger particles, approximately 1000 times bigger than previously thought. This research was published on September 19 in the journal Nature Nanotechnology.
“There are numerous methods to generate renewable energy, but the critical aspect is how to store it,” explained Han-Ming Hau, a battery technology researcher with Berkeley Lab’s Ceder Group and a PhD student at UC Berkeley. “By implementing our innovative approach, we can utilize a material that is abundant and affordable, requiring less energy and time to produce compared to some current lithium-ion battery cathode materials. Additionally, it can store energy efficiently and perform equally well.”
The team employed a groundbreaking two-day procedure that begins by extracting lithium ions from the cathode material, followed by heating it at low temperatures (around 200 degrees Celsius). This represents a significant contrast to the traditional process for manganese-based DRX materials, which typically spans over three weeks.
Using advanced electron microscopes, the researchers captured detailed atomic-scale images of the manganese-based material during operation. They discovered that this new process allowed the material to develop a nanoscale semi-ordered structure, which significantly improved battery performance by enabling dense energy storage and delivery.
Additionally, the team used various X-ray techniques to investigate how battery cycling induces chemical changes in manganese and oxygen at a larger scale. By analyzing the behavior of manganese material across different scales, the researchers have opened up new avenues for producing manganese-based cathodes and gained insights into the nano-engineering of future battery materials.
“We now have a clearer understanding of the material’s distinctive nanostructure,” Hau remarked. “We also have a synthesis method that initiates a ‘phase change’ in the material, thereby enhancing its electrochemical performance. This is a crucial advancement that brings this material closer to practical battery applications.”
This research utilized resources from three user facilities supported by the DOE Office of Science: the Advanced Light Source and Molecular Foundry (National Center for Electron Microscopy) at Berkeley Lab, and the National Synchrotron Light Source II at Brookhaven National Laboratory. It was funded by the Office of Energy Efficiency and Renewable Energy and the Office of Science within the DOE.
