Ultrafast and ultrastable Na-ion storage in zero-strain sodium perylenetetracarboxylate anode enabled by ether electrolyte

Abstract

For sodium-ion batteries (SIBs), organic anode materials, especially sodium carboxylates, received increasing attentions due to their performance potential and resource sustainability. Unfortunately, previous studies have exhibited inferior electrochemical performance, for which we speculate the use of conventional but improper ester electrolytes is responsible to a large extent. To prove it, we have systematically investigated the electrochemical performance and behaviors of two typical carboxylates, namely tetrasodium 1,4,5,8-naphthalenetetracarboxylate (Na4NTC) and tetrasodium 3,4,9,10-perylenetetracarboxylate (Na4PTC), in the typical ester and ether electrolytes. To our surprise, in the ether electrolyte, Na4PTC shows exceptional ultrafast and ultrastable Na-ion storage performance (the capacity retention is 77% at 5000 mA g–1, or 95% after 20,000 cycles), both of which set new records for organic anode materials. In-depth mechanism analysis reveals that the scarce zero-strain character of Na4PTC leading to high crystalline structure stability and high Na ion diffusion coefficient (5 × 10–10 cm2 s–1), as well as the thin and robust SEI derived from the ether electrolyte, are the internal and external factors of the excellent performance, respectively. Finally, a demonstration of Na4PTC–Na3V2(PO4)3 full-cell shows the huge potential of Na4PTC anode in practical applications, especially those emphasizing high power and long life.