There is a growing need for rechargeable lithium-ion batteries as a transition to "greener" energy sources. Nonetheless, most of their cathodes are made of cobalt, a metal whose extraction has significant negative social and environmental effects.
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Researchers have now evaluated a carbon-based cathode material that is abundant on Earth and could replace cobalt and other hazardous and scarce metals without compromising the performance of lithium-ion batteries, as reported in ACS Central Science. Lithium-ion batteries power everything these days, including electric cars, laptops, and cell phones.
One of the obstacles to achieving a worldwide switch to renewable energy sources, especially for the conversion from gas-powered to electric vehicles, is the scarcity and difficulty of mining metals like cobalt, nickel, and magnesium, which are necessary for rechargeable battery cathodes.
Prior studies have created cathodes from less expensive and more widely available carbon-containing materials, such as carbonyl compounds and organosulfur. Still, the energy output and stability of those prototypes fell short of that of conventional lithium-ion batteries. Thus, Mircea Dincă and associates sought to investigate the possibility of greater success with alternative carbon-based cathode materials.
They might have discovered bis-tetraaminobenzoquinone (TAQ) to be a good candidate. Layered solid-state structures formed by TAQ molecules can rival conventional cobalt-based cathode performance. Expanding upon their earlier research demonstrating TAQ's efficacy as a supercapacitor material, Dincă's group examined the substance in a lithium-ion battery cathode.
They added compounds containing rubber and cellulose to the TAQ cathode to boost the adhesion of TAQ to the stainless steel current collector of the cathode and to improve cycling stability. The new composite cathode provided an energy density higher than most cobalt-based cathodes cycled more than 2,000 times safely and charged-discharged in as little as six minutes in the researchers' proof-of-concept demonstration.
Before the TAQ-based cathodes are commercialized, more testing is required. Still, the researchers are hopeful that they could pave the way for the development of high-energy, long-lasting, and quickly rechargeable batteries that would accelerate the world's shift to renewable energy sources devoid of cobalt and nickel.
Automobili Lamborghini S.p.A funded the research.
Journal Reference:
Fujii, S., et.al., (2023). Discovery of Unconventional Proton‐Conducting Inorganic Solids via Defect‐Chemistry‐Trained, Interpretable Machine Learning. Advanced Energy Materials. doi.org/10.1002/aenm.202301892.