Synthesis of Hollandite‐Type Manganese Dioxide with H+ Form for Lithium Rechargeable Battery

A hollandite-type manganese dioxide (HolMO), without foreign metal cations (K[sup +], NH[sup +][sub 4], Na[sup +]) in the (2 [times] 2) tunnel, was prepared directly by reacting LiMnO[sub 4] with Mn(NO[sub 3])[sub 2] in an H[sub 2]SO[sub 4] acidic solution. The HolMO belonged to a body-centered tetragonal system (space group 14.m) and could be expressed by the formula H[sub 4x]Mn[sub 8[minus]x]O[sub 16][center dot]yH[sub 2]O. A preliminary electrochemical study suggested that the HolMO is promising as the cathode for a lithium rechargeable battery.