Next Generation Lithium Metal Battery Uses Gel Polymer Electrolyte. Why?
By Josh Nicolas
Highly adaptable SEI/CEI interfacial layers enabling remarkable performance of high-nickel solid-state batteries
Qing Liu, Yongjiang Sun, Shimin Wang, Qi An, Lingyan Duan,Genfu Zhao, Changhong Wang, Kieran Doyle-Davis, Hong Guo, Xueliang Sun
Recently, a group of researchers from Yunnan University and the University of Ontario has designed a new Gel Polymer Electrolyte (GPE). This new technology further enhance the room temperature operation capacity and lithium metal ability to be used as anode for the battery.
There are advantages of GPE over liquid electrolytes and solid electrolyte. First, it is better in operating temperature compared to existing solid polymer electrolyte which has 60 degree operation temperature. This GPE can work in room temperature which is the most suitable option for room temperature application. Second, safety is better in GPE, due to lower leakage risk compared to former liquid electrolyte used in most smartphones today. Third, this new technology will enable smaller battery size due to its higher energy density. The use of new SEI layer (Lithium Fluoride) in this research has been proven to supress the dendrite growth, which allows the use of higher energy density Lithium Metal Battery (LMB). In fact, the group has designed and tested their LMB to prove the advantages of their GPE. The use of lithium metal instead of graphite has also been a popular discussion of scientific community.
To make Gel Polymer Electrolyte (GPE), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.25M lithium tetrafluoroborate salt (LiBF4, 99.9%) is dissolved in Ethylene Carbonate (EC), 1,3-Dioxolane (DOL). The gelation process takes about 24 hours. This GPE will be used in the anode and cathode half cell. Special treatment is also done for the cathode. The cathode uses NCM 811 (electrode consists of Nickel, Cobalt, and Manganese) with added aluminum isopropoxide (AIP). The cathode will later form CEI (Cathode Electrolyte Interface) and it has important role in boosting charge transfer and provide sufficient interfacial ion diffusion. While the anode forms SEI layer with help of LiTFSI and LiBF4. This new SEI layer capability to prevent dendrite growth is also the main focus and important breakthrough of this research.
I hope that this new battery could replace current lithium ion battery that has also been a safety issue that needs to be tackled. If new battery that can store more energy with the same physical dimension, wouldn't our lives be changed?
