A group of Chinese researchers has found a way of using captured atmospheric nitrogen in a battery
Despite various breakthroughs in battery technology, we still rely on tried-and-tested Li-ion, mainly because it's cheap. In the hunt for an alternative that won't break the bank, is more environmentally friendly and sustainable, researchers from China have discovered a way to generate power from nitrogen gas – one the most abundant gases in the world.
Nitrogen makes up almost 80 per cent of our atmosphere but nitrogen gas, which consists of two nitrogen atoms held together by a strong triple covalent bond, doesn't break up easily under normal conditions. This makes it difficult to transfer the chemical energy of the bond into electricity.
Now, a group of researchers from the Changchun Institute of Applied Chemistry has outlined one way atmospheric nitrogen can be captured and used in a battery for next-generation energy storage systems.
The "proof-of-concept" design reverses the chemical reaction that powers existing Lithium-nitrogen batteries.
“We have demonstrated that electrochemical N2 fixation in ambient conditions is possible with rechargeable Li-N2 batteries,” the authors explained. Instead of generating energy from the breakdown of lithium nitride into lithium and nitrogen gas, the battery prototype runs on atmospheric nitrogen in ambient conditions. This reacts with lithium to form lithium nitride.
The energy output is comparable to other lithium-metal batteries, the authors said.
"This promising research on a nitrogen fixation battery system not only provides fundamental and technological progress in the energy storage system," said lead author Xin-Bo Zhang.
“The work is still at the initial stage. More intensive efforts should be devoted to developing the battery systems."
The process could also help make other processes more environmentally friendly.
“The conversion of atmospheric nitrogen (N2) into valuable substances such as fine chemicals and fertilisers is critical to industry, agriculture, and many other processes that sustain human life,” the authors continued.
Up until now, converting nitrogen has heavily relied on the energy – and capital–intensive Haber-Bosch process. In this process, H2 and energy is largely derived from fossil fuels, meaning large amounts of carbon dioxide are given off. The new battery could get around this problem.
"The research on Li-N2 battery systems is still at the initial stage," Zhang told WIRED. "Li-N2 battery still faces many challenges, and the stability of Li anode, cathode and electrolyte should be improved, more effective nitrogen fixation catalysts should be developed, and battery reaction mechanism should be further studied. If these issues are resolved, the Li-N2 battery will be available to the public."