Fig. 5

Analytical characterization of ex situ cycled electrode after 3rd and 100th cycles. a Radial intensity profiles acquired from the SAED patterns of electrode at pristine state, discharged, and charge at the 3rd cycle and discharge and charge at the 100th cycle. EELS spectra showing valence changes of iron between discharged and charged states of electrode cycled b 3 times and c 100 times. Dis. and Ch. indicate discharged state and charged state, respectively. Typical morphology and corresponding FFT of d, e electrode after three cycles and f, g electrode after 100 cycles. RS at inset of g denotes rock-salt phase. Scale bars in d, f 10 nm, scale bars in e, g 5 nm