Internal structure – Na storage mechanisms – Electrochemical performance relations in carbons

This review focuses on carbon-based sodium ion battery (NIB) negative electrodes, emphasizing the internal structure – Na storage mechanisms – electrochemical performance relations. We bring a unique vantage to the ever-expanding field of NIB anode literature: To quantify the critical emphasis on the structure – properties interdependence, we provide comprehensive data comparisons of representative published studies. This is accomplished through a series of “Master Plots”, which rather than focusing on an individual publication, combine the data by broad features first outlined in the taxonomy section. The advantage of such an approach is that it transcends the paper-to-paper differences in electrochemical performance in a given class of anodes, providing generalizable comparisons that are statistically significant. For instance, we manage to demonstrate that, while N-doped carbons have a slight advantage in terms of capacity, their rate performance at higher currents is unchanged over that of undoped carbons. To our knowledge such broad high-level data analysis has not been done in past reviews on either NIB or LIB carbon anodes. Furthermore, we also discuss a wide range of individual microstructures and chemistries, offering critical analysis when appropriate.