Excess volume in nanocrystalline lithium-carbon system

A method that combines model calculations with X-ray diffraction analyses on prepared nanocrystalline samples has been developed to determine the excess volume and its dependence on grain size in nanocrystalline anode materials. In the model calculations, the geometry of grains in nanocrystalline systems is treated as a spherical shape for simplicity. It has been determined that the excess volume depends on grain size and atomic density at grain boundaries. The nanocrystalline Li₂C₂ alloy was taken as an example of the nanostructured anodes and its grain boundary expansion was generated by the excess volume at different grain size levels.