We can trace the history of electrochemical cells just over two hundred years back to Luigi Galvani and Alessandro Volta¿s inventions, and perhaps more than a millennium further to the Baghdad/Parthian battery apparently used for electroplating in ancient Mesopotamia. Now batteries are of immense technological importance in building the environmentally sustainable society of tomorrow. Here we propose to use muons to measure the lithium diffusion rate in a series of battery materials with growing industrial significance - one of the key properties of these materials, and difficult to determine with other techniques. This involves carrying out weak longitudinal field measurements at a series of temperatures to determine the influence of the lithium diffusion on the distribution and fluctuation rate of the magnetic fields at the muon stopping sites.