Elastic and plastic mechanical properties of lithium measured by nanoindentation

Metallic lithium is the desired anode material for high energy density solid state batteries, and shows a factor of four range in elastic modulus and two orders of magnitude difference in creep properties dependent on sample preparation and testing method.

In the paper 'Elastic and plastic mechanical properties of lithium measured by nanoindentation' published in Materials & Design, a team of researchers from this department, led by Dr Ed Darnbrough, used in-situ nanoindentation to measure the anisotropic mechanical properties from the BCC crystal structure and the effect of strain-rate and temperature, which have an impact on battery cycle performance.  

The work clarifies the reasons for the range of property values reported in the literature with a global equation for yield strength with strain-rate.  From this information, conclusions can be drawn around variables to optimise in order to minimise the required pressure for a chosen stripping critical current in solid state batteries.