Penn State researchers recently revealed that possibility of creating rechargeable lithium metal batteries with augmented energy density, performance & safety. They are planning on using a newly created, solid-electrolyte inter-phase to accomplish this.
With increasing need for advanced energy density lithium metal batteries which is used for cellphones, drones & electric vehicles. Solid electrolyte inter phase’s stability has been an important issue in stopping their development due to the presence of a salt layer on the battery’s lithium electrode’s surface has been seen to protect it & run lithium ions.
Donghai Wang’s Explanation
Penn State’s Professor Donghai Wang says that the layer is quite essential. It is naturally created by the reaction between electrolyte & lithium in the battery. However, it doesn’t conduct efficiently which creates plenty of issues. SEI’s deterioration backs the creation of dendrites, which is an element of lithium metal batteries. They are needle-like formations developing from battery’s lithium electrode. Furthermore, they impact performance & safety in a negative way. An approach to this issue was released by researchers in Nature Materials.
Professor Donghai says that this is the reason lithium metal batteries are not durable – interphase increases & is unstable. For this research, they utilized a polymer composite to develop a better SEI.
Enhanced SEI is a reactive polymer composite created of lithium fluoride nanoparticles, polymeric lithium salt and graphene oxide sheets. The different makeup of this battery element include slim layers of the said materials. It is in this particular sector, Thomas E. Mallouk lent his expertise.
Thomas explains that plenty of molecular-level control is required to accomplish steady lithium interface. Polymer developed by Donghai & Yue reacts to create a claw-like bond to metal surface of lithium. It provides surface of lithium whatever it demands in an un-resisting manner so that it doesn’t respond with molecules in the electrolyte. Nanosheets in composite function as a mechanical restraint to stop dendrites from creating from lithium metal.
Using both chemistry & engineering design, relation between fields helped the technology to control lithium surface at atomic level. Thomas further adds that when they create batteries, they don’t normally think like chemists, completely to molecular level. However, that’s what they had to do here. Reactive polymer also has the potential to decrease production weight & price. This in turn enhances the potential of lithium metal batteries. With steady SEI, it becomes possible to increase energy density of present batteries, creating them to last a bit longer and also to be safe.