There are many strands of research into the development of batteries. This includes improving batteries currently in use, configuring batteries for next generation technology, and considering the environmental impact from battery use and disposal. With this latter point, next-generation batteries that store more energy are critical if society is to achieve the UN’s Sustainable Development Goals and realize carbon neutrality.
As an example of the environmental impact, one study found that the sourcing of lithium, from both a process and location perspective, can strongly affect its associated environmental impacts.
This means having batteries that last longer, are rechargeable, and therefore need disposing less often. A limitation with developing such batteries is the tendency for the batteries to exploded as they release oxygen.
Avoiding exploding batteries
A new insight has arisen relating to the release of oxygen in lithium-ion batteries. This could lead to more robust and safer high-energy-density rechargeable batteries. There is a limitation that affects battery development, something defined as a ‘thermal runway’. It follows that the higher the energy density, the higher the likelihood of the overheating of batteries. In extreme cases, this can lead to batteries exploding.
This happens as oxygen is released from cathode active material. Whie scientists know this happens, they are less clear as to why it happens. Seeking a way to make batteries safer, Tohoku University scientists have looked into a primary trigger of the thermal runaway effect: oxygen release.
Focusing on lithium-ion batteries LiNi1/3Co1/3Mn1/3O2 (NCM111). Using NCM111, the researchers developed a model oxide-based battery material through experimental techniques including coulometric titration and X-ray diffractions.
In attempting to pinpoint the explosion factor, the research team found that when oxygen is released, it reduces the transition metals (Ni, Co and Mn in NCM111).This decreases the ability of these metals keep a balanced charge in the materials, leading to oxygen release and the danger of an exploding battery.
To overcome these effects, the researchers are proposing that the high valent transition metals be used to destabilize lattice oxygen in oxide-based battery materials. This could open the door to a true environmentally-friendly battery solution.
The new battery research appears in the journal Advanced Energy Materials and it is titled “Lattice Oxygen Instability in Oxide‐Based Intercalation Cathodes: A Case Study of Layered LiNi 1/3 Co 1/3 Mn 1/3 O 2.”
