Sodium ion batteries (NIB) are promising alternatives to the current lithium ion batteries: sodium is cheap, sustainable, and has similar properties to lithium. Search for an effective anode for NIBs focuses on hard carbon (HC), which can be made from cheap biomass sources. HC can also be used to make carbon fibres (CF), making structural batteries possible, where CF act as both load bearers and electrodes. The structure of HC is debated, but it is accepted that it contains both amorphous and graphitic elements, and four possible Na+ storage sites have been identified. We wish to use total neutron scattering to study the relationship between HC microstructure, before and after conversion into CF, and its capacity as an anode in NIB using lignin-derived HC.