Australian Nuclear Science and Technology Organisation 1 article published in JoVE Engineering In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries William R. Brant1, Siegbert Schmid1, Guodong Du2, Helen E. A. Brand3, Wei Kong Pang2,4,5, Vanessa K. Peterson4, Zaiping Guo2,5, Neeraj Sharma6 1School of Chemistry, University of Sydney, 2Institute for Superconducting & Electronic Materials, University of Wollongong, 3Australian Synchrotron, 4Australian Nuclear Science and Technology Organisation, 5School of Mechanical, Materials, and Mechatronic Engineering, University of Wollongong, 6School of Chemistry, University of New South Wales We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.