Figure 7: Reversibility analysis of the electrodes.
From: Highly durable organic electrode for sodium-ion batteries via a stabilized α-C radical intermediate
O K-edge XANES spectra of TSAQ (a) and DCCA (b) electrodes at different states; N K-edge XANES spectra (c) and N1s XPS (d) of the TSAQ electrode at different states. N1s spectra, the positive shift of binding energy demonstrates a higher oxidation state than primary state. Comparing with the primary state, the N1s variation: 1.0 V (−0.06 eV); 0.5 V (+0.6 eV); 0.05 V (−0.32 eV); 1.5 V (+0.07); and 3 V (−0.06 V). For a,c,d: black, as-made; red, discharge to 1.0 V; olive, discharge to 0.5 V; blue, discharge to 0.05 V; magenta, recharge to 1.5 V; and violet, fully recharge to 3 V.
