Neeraj Sharma and Marnix Wagemaker

Abstract The effort of material scientists in the discovery, understanding, and development of Li-ion batteries largely depends on the techniques available to observe the relevant processes on the appropriate time and length scales. This chapter aims at demonstrating the role and use of different neutron-scattering techniques in the progress of Li-ion battery electrode and electrolyte properties and function. The large range in time and length scales offered by neutron-scattering techniques is highlighted. This illustrates the type of information that can be obtained, including key parameters such as crystal structure, Li-ion positions, impact of nano-particle size and defects, ionic mobility, as well as the Li-ion distribution in electrodes and at electrode-electrolyte interfaces. Special attention is directed to the development of in situ neutron-scattering techniques providing insight on the function of battery materials under realistic conditions, a promising direction for future battery research.