Surface-modified maghemite as the cathode material for lithium batteries

✍ Scribed by James Manuel; Jae-Kwang Kim; Jou-Hyeon Ahn; Gouri Cheruvally; Ghanshyam S. Chauhan; Jae-Won Choi; Ki-Won Kim

• Book ID: 104025103
• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 853 KB
• Volume: 184
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2008.02.079

✦ Synopsis

The inorganic-organic hybrid maghemite (␥-Fe 2 O 3 )/polypyrrole (PPy) was synthesized and evaluated as cathode-active material for room temperature lithium batteries. The nanometer-sized core-shell structure of the hybrid consisting of the maghemite core with surface modified by PPy was evidenced from the morphological examination. The cathode fabricated with the as-prepared hybrid material delivered an initial discharge capacity of 233 mAh g -1 and a reversible capacity of ∼62 mAh g -1 after 50 charge-discharge cycles. A much higher performance with an initial discharge capacity of 378 mAh g -1 and a reversible capacity of ∼100 mAh g -1 was achieved with the cathode based on the segregated active material, which was obtained by subjecting the as-prepared hybrid material to an additional ball-milling process. The study demonstrates the promising lithium insertion characteristics of the nanometer-sized core-shell maghemite/PPy particles prepared under optimized conditions for application in secondary batteries.