Linking pore-size, local atomic structure and electrochemical properties in hard carbon anodes for sodium-ion batteries

Hard carbons are promising anode materials for sodium-ion batteries. However, explicitly linking electrochemical properties to the underlying structural mechanisms, and ultimately the synthetic route, is challenging due to the disordered, multi-length scale features of both the carbons themselves, and the sodium-insertion products. Here we propose to collect small- and wide-angle (total scattering) data on a series of hard carbons with a range of average pore sizes as a function of Na-insertion to determine which areas of the carbon are suitable for the formation of quasimetallic sodium nanoclusters, giving clues as to whether pore size or local structural/electronic environment limits the cluster size and hence low-voltage capacity.