Lithium-ion batteries use toxic, heavy metals, such as lithium and cobalt, which can negatively impact the environment when they are extracted as well as disposed. Now, researchers from York University have discovered a way to make lithium-powered batteries more environmentally friendly, while retaining performance, stability and storage capacity.
Organic materials are a promising alternative to currently used inorganic metals, something that Professor Thomas Baumgartner and his team at York are busy developing. “Organic electrode materials are considered to be extremely promising materials for sustainable batteries with high power capabilities,” he says.
Their latest breakthrough is the creation of a new carbon-based organic molecule that can replace the cobalt now used in cathodes found in in lithium-ion batteries. The new material addresses the shortcomings of the inorganic material while still maintaining performance.
“Electrodes made with organic materials can make large-scale manufacturing, recycling, or disposing of these elements more environmentally friendly,” says Baumgartner. “The goal is to create sustainable batteries that are stable and have equally as good if not better capacity.
“With this particular class of molecules that we’ve made, the electroactive component is very suitable for batteries as it’s very good at storing electrical charges and has good long-term stability.”
Baumgartner and his group previously reported on the electroactive component in a paper published in the journal Advanced Energy Materials. “We have optimized this electroactive component and put it in a battery. It has a very good voltage, up to the 3.5 volts, which is really where current batteries are now,” he says. “It’s an important step forward in making fully organic and sustainable batteries.”
Baumgartner, along with postdoctoral researchers Colin Brides and Monika Stolar, have also demonstrated that this material is stable in long-term operation with the ability to charge and discharge for 500 cycles. One of the downsides of inorganic electrodes is that they generate significant heat when charging and require limited discharging rates for safety reasons; this new molecule addresses that shortcoming.
The next step, says Baumgartner, is to improve the capacity further. His team is currently developing the next generation of molecules that show promise in being able to increase current capacity.
Research article available at C.R. Bridges, et al. Batteries & Supercaps, 2020, doi.org/10.1002/batt.201900164