Enhancing glass anode performance for lithium‐ion batteries via crystallization

We investigate the thermal and electrochemical properties of xFe 2 O 3 ‐(100‐x) P 2 O 5 glass (x = 20, 30, 40, and 50 mol%) and 50Fe 2 O 3 ‐50P 2 O 5 (50FeP) glass‐ceramics as anodes for lithium‐ion batteries (LiBs). The results show that both the glass transition temperature and the energy bandgap monotonically decrease with the increasing Fe 2 O 3 while a critical Fe 2 O 3 content of 30 mol% is found to give glass the highest thermal stability, the largest capacity at 1 Ag ‐1 , and the lowest charge‐transfer resistance before cycling. Moreover, Fe 3 (P 2 O 7 ) 2 crystals formed during heat treatment in 50FeP glass effectively enhances the electrochemical properties. The optimum heat treatment condition for 50FeP glass is found at 1033 K for 4 h, that is, 1033 K‐4 h sample enables a reversible capacity of 237 mA h g −1 at the end of 1000 cycles at 1 Ag ‐1 , which is more than 1.5 times higher than that of the 50FeP glass‐based anode. These findings suggest that the Fe 2 O 3 ‐P 2 O 5 glass‐ceramics hold significant potential for the effective development of new types of glass anodes for future advanced LiBs.