On the use of the reverse micelles synthesis of nanomaterials for lithium-ion batteries

The reverse micelles procedure is a convenient route for the preparation of nanomaterials. Chemical reactions in aqueous media are carried out within a restricted volume, limited by the array of surfactant molecules. The versatility of this technique allows its use in the preparation of different electrode materials for lithium-ion batteries. The thermolysis of the reagents in aqueous solution in the micellar volume by contact with hot kerosene allows the preparation of LiCoO₂, LiMn₂O₄, and LiNi_0.5Mn_1.5O₄ fine powders with good electrochemical behavior. The conversion electrode material Co₃O₄ was prepared with controlled particle size and microstructure by a precipitation reaction in the micellar volume. The electrochemical response found in lithium cells was excellent after optimizing the annealing procedure. Cobalt and iron oxalate nanoribbons and submicrometric rhombic particles of manganese carbonate have been prepared by the reverse micelles procedure and partially behave as conversion oxide electrodes. The electrochemical reaction with lithium of these new oxysalt materials takes place by a different conversion reaction than the corresponding oxide, and a surface capacitive contribution has also been detected.