Quantification of Early Stage Lithium Dendrite Growth Force Using In-Situ Transmission Electron Microscopy

摘要

It is well known that a flood of technological advances will follow the creation of a reliable high performance battery. Theoretically there exists a solid state Lithium metal battery that would meet many of the necessary energy demands, but Li dendrite growth creates poor cyclability and safety concerns which currently prevent this battery from existing on the market.A new experimental technique to obtain the growth force of a Li dendrite was investigated to gain insight into the early stages of this destructive phenomenon. Two wires were placed into a Nanofactory STM TEM holder. The first wire's tip contained Li metal flakes. A conductive AFM cantilever was attached to the end of the second wire. The Li metal and tip of the cantilever were made to contact inside the TEM and a potential was applied, initiating the growth of Li and causing the displacement of the AFM cantilever. Measurement of the cantilever deflection revealed the early stage lithium dendrite growth force to be between 3 to 14.5 MPa. This result, paired with our current and advancing knowledge of Li dendrite formation and growth, will be useful in the selection of solid state electrolytes with properties that inhibit dendrite initiation and/or propagation.