Figure 1.

(a) SEM image and photograph of cellulose–PAN separator; (b) SEM image of cellulose–PAN–Al₂O₃ composite separator; (c) SEM image and EDX mapping data (Al, C, O elements) of cellulose–PAN-Al₂O₃ composite separator; (d) SEM image on side for cellulose–PAN-Al₂O₃ composite separator (inset: SEM image of cellulose–PAN-Al₂O₃ composite separator at pierced point). (e) The magnified SEM image of cellulose–PAN-Al₂O₃ composite separator with EDX mapping result for Al, C, and O elements. (f) XRD pattern of bare and cellulose–PAN-Al₂O₃ composite separator; (g) ToF-SIMS data of cellulose–PAN-Al₂O₃ composite separator for AlO⁺ (m = 42.97) fragment.