Amorphous manganese dioxide: A high capacity lithium intercalation host

Abstract

Amorphous manganese dioxide (a-MnO2) has been synthesized via a room-temperature sol-gel route. The material is a stable intercalation host for lithium and the intercalation capacity is greater than 1.6 mol of Li per mole of MnO2. The host remains amorphous in the entire intercalation range and the insertion process is reversible. When used as an intercalation electrode, the material stores energy at the level of 1056 mWh/g. The latter represents an improvement over crystalline manganese oxide materials by factors of two to three. © 1998 The Electrochemical Society, Inc.