Reactive and Nonreactive Ball Milling of Tin‐Antimony (Sn‐Sb) Composites and Their Use as Electrodes for Sodium‐Ion Batteries with Glyme ElectrolyteLatest updated: May 29, 2020
Authors: Wolfgang Brehm Johannes Rolf Buchheim Philipp Adelhelm
Sodium-ion batteries (SIBs) are considered as attractive futureenergy stores which could complement the more mature Li-ionand lead-acid technologies.[1–5]Considering potential negativeelectrodes, the use of graphite is not straightforward in SIBsdue to the lack of sodium-rich NaCxcompounds. This can becircumvented by use of solvent cointercalation reactions thoughthe obtainable capacity of about110 mAh g1is still limited.[6–9]The useof hard carbon is one promising optionwith capacities up to about 400 mAh g1,but the partly extremely low redox potentialversus Naþ/Na might easily lead to den-drite formation during charging. In viewof these challenges, the use of metals (ormetalloids) appears attractive which typicallyprovide high capacities at attractive redoxpotentials. However, the use of silicon,which is widely studied for lithium-ion bat-teries (LIBs), also has failed in SIBs so far.For this reason, a lot of interest is currentlydevoted to the use of tin (Sn) and antimony(Sb).[11–17]In both cases, the redox reactioninvolves several phase transitions and there-fore the potential curve has a more steppedshape. The major redox potentials of Sn andrespectively Sb in sodium cells are at about0.2 and 0.6 V versus Naþ/Na, which makestheir use very appealing. In lithium cells, theredox potentials are about 0.5 and 0.9 Vversus Liþ/Li. Moreover, when comparing the sodiation/lithiationof Sn and Sb in SIBs and LIBs, it is quite interesting to note thatstructural stability was found to be better for the case of sodium,despite its larger atom/ion size.[18,19]This indicates that the differ-ence between analogue reactions for“lithium”and“sodium”canbe also counterintuitive.