作者
Gaofeng Li,Junxiao Wang,Jun Chu,Minle Li,Zijun Hu,Feng Wang,Yan Han,Taotao Cai,Zhiping Song
摘要
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 (Na 4 NTC) and tetrasodium 3,4,9,10-perylenetetracarboxylate (Na 4 PTC), in the typical ester and ether electrolytes. To our surprise, in the ether electrolyte, Na 4 PTC 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 Na 4 PTC leading to high crystalline structure stability and high Na ion diffusion coefficient (5 × 10 –10 cm 2 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 Na 4 PTC–Na 3 V 2 (PO 4 ) 3 full-cell shows the huge potential of Na 4 PTC anode in practical applications, especially those emphasizing high power and long life.