Lithium metal battery breakthrough offers rapid recharging

The research from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) describes a new way to make solid state batteries with a lithium metal anode. The research is published in Nature Materials. 

“Lithium metal anode batteries are considered the holy grail of batteries because they have ten times the capacity of commercial graphite anodes and could drastically increase the driving distance of electric vehicles,” Xin Li, Associate Professor of Materials Science at SEAS and senior author, said in a statement.

A significant challenge in the design of these batteries is the formation of dendrites on the surface of the anode. These structures grow into the electrolyte and pierce the barrier separating the anode and cathode, causing the battery to short or catch fire. 

Dendrites form when lithium ions move from the cathode to the anode during charging, attaching to the surface of the anode in a process called plating that creates an uneven, non-homogeneous surface and allows dendrites to form. When discharged, that coating needs to be stripped from the anode and when plating is uneven, the stripping process can be slow and result in potholes that induce more uneven plating in the next charge.