Advancements in Cobalt-Free Battery Technology Emerge from University of Tokyo

Researchers at the University of Tokyo have developed an innovative cobalt-free alternative to lithium-ion batteries that outperforms existing technology in both longevity and performance, with prospective applications across various electrochemical processes.

Substituting cobalt in batteries mitigates its environmental and social consequences.

Rechargeable batteries of high capacity and reliability are indispensable in multiple devices and forms of transportation. They are instrumental in the global transition towards sustainability. A myriad of elements, including cobalt, are employed in their fabrication. Cobalt extraction, however, raises concerns related to environmental degradation, economic impact, and societal repercussions. For the first time, scientists from the University of Tokyo have put forth a cobalt-free alternative that not only meets but surpasses conventional battery technologies in certain aspects. This new technology demonstrates durability over an extensive range of recharge cycles, and its underlying principles could extend to solving other issues.

The Pervasiveness and Complications of Lithium-Ion Batteries

It is likely that you are accessing this article through a laptop or a smartphone, or at the very least, you possess one such device. Inside these, and other gadgets, lithium-ion batteries (LIBs) can be found. For many years, LIBs have been the go-to source for powering portable electronic equipment.

As the world seeks alternatives to fossil fuels, these batteries play a significant role in electrifying automobiles and in residential energy storage for those employing solar panels. Despite their merits, LIBs also present drawbacks.

By substituting cobalt—a resource-limited and problematic element—with elements that are more plentiful and environmentally benign, the researchers have alleviated some of the existing battery issues. Additionally, the newly developed battery technology enhances energy density in terms of weight and volume, a benefit especially pertinent in applications such as electric vehicles. Credit: ©2023 Yamada et al. CC-BY-ND

Indeed, while LIBs rank among the most energy-dense portable power solutions, many desire an even greater energy density to extend battery life or power more resource-intensive applications. Although LIBs can undergo numerous recharging cycles, they deteriorate over time; a longer-lasting battery would benefit all users. But perhaps the most concerning drawback stems from the elemental composition required for their construction.

The Cobalt Conundrum

Cobalt is a critical ingredient in the electrodes of LIBs. Batteries essentially operate by facilitating the movement of lithium ions between two electrodes, positive and negative, in an electrolyte when connected to an external circuit. Cobalt is a rare element, primarily sourced from mines in the Democratic Republic of Congo. These mines have long been associated with environmental degradation and poor labor conditions, including child labor. Supply chain complications arise due to political and economic instabilities in the region.

“In our quest to improve lithium-ion batteries, the transition away from cobalt presents both a technical challenge and an opportunity for multi-faceted impact—encompassing environmental, economic, social, and technological aspects,” said Professor Atsuo Yamada from the Department of Chemical System Engineering. “We have successfully replaced cobalt with a new composite of elements in the electrodes, comprising lithium, nickel, manganese, silicon, and oxygen—elements that are far more abundant and far less problematic.”

Promising Progress

The cobalt-free electrodes and electrolyte designed by Yamada and his team not only eliminate cobalt but also improve existing battery chemistry in certain areas. The energy density of the new LIBs is approximately 60% higher, translating to longer battery life. Moreover, these batteries can deliver 4.4 volts as opposed to the standard 3.2-3.7 volts. One of the most impressive advancements is the enhancement in rechargeability. Test batteries utilizing the new chemistry managed to maintain about 80% of their storage capacity after over 1,000 charge-discharge cycles (approximating three years of comprehensive use).

“While we are pleased with the advancements made, the journey was fraught with technical challenges. We had to meticulously counteract various undesirable chemical reactions that threatened the longevity of the new battery formulations,” Yamada stated. “There are still some minor issues to resolve for even greater safety and durability, but at this stage, we are optimistic that our research will contribute to the development of improved batteries across a range of applications.”

Yamada and his team also recognize that their findings could have implications beyond LIBs, extending to other electrochemical operations and devices, such as water electrolysis, ore smelting, and electro-coating, among others.

Reference: “Electrolyte design for lithium-ion batteries with cobalt-free cathode and silicon oxide anode” by Seongjae Ko, Xiao Han, Tatau Shimada, Norio Takenaka, Yuki Yamada, and Atsuo Yamada, 19 October 2023, Nature Sustainability.
DOI: 10.1038/s41893-023-01237-y

Frequently Asked Questions (FAQs) about Cobalt-free lithium-ion batteries

More about Cobalt-free lithium-ion batteries

• University of Tokyo’s Official Website
• Nature Sustainability Journal
• Environmental Impact of Cobalt Mining
• Current State of Lithium-Ion Batteries
• Electrochemical Processes and Applications