Birnessite manganese dioxide synthesized via a sol—gel process: a new rechargeable cathodic material for lithium batteries

✍ Scribed by S. Bach; J.P. Pereira-Ramos; N. Baffier; R. Messina

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 834 KB
• Volume: 36
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(91)85012-v

✦ Synopsis

In comparison with the classical bimessite compound synthesized by a conventional reaction, sol-gel lamellar bimessite having the formula MnO ,,84,0.6H20 exhibits an important preferred orientation. Electrochemical Li insertion in this compound occurs in two reduction processes in both galvanostatic and voltammetric curves: the first (0 c x c 0.4) occurs between 4.25 and 2.85 V with a high kinetic transport and a strong decrease of the interlayer spacing, the second (0.4 c x < 0.9) occurs at 2.8 V with slower kinetics and no variation of the c parameter. Cycling capacity studies show that the sol-gel bimessite is the most promising rechargeable manganese dioxide with a high d.o.d. of 75% of the initial capacity (200 A h kg-') reached after the fiftieth cycle.