This technology produces high-capacity, high-crystallinity lithium-manganese composite oxides by synthesizing amorphous manganese-transition metal (V or Nb) composite precipitates via a reduction-precipitation method, followed by mixing with lithium compounds and calcining at low temperatures.
Conventional manganese-based cathode active materials, such as LiMnO2, suffer from low structural stability, leading to structural collapse and reduced capacity and efficiency during repeated charge-discharge cycles. Furthermore, they are limited by the formation of impurities during high-temperature calcination.
This technology uses a reducing agent, such as NaBH4, to co-precipitate manganese and a dissimilar metal (V or Nb) into an amorphous phase. This is then mixed with a lithium compound and subjected to a two-stage heat treatment at a relatively low temperature of 300–800°C to obtain a single-phase oxide with the composition Li1+a(Mn1-bMb)1-aO2. It can be applied to mass-production lines for cathode materials where calcination energy costs must be reduced, or to low-cost manganese-based cells for energy storage. Thanks to the atomic-level mixing of the precursor, it is possible to obtain crystals with uniformly distributed dissimilar metals even at low temperatures.
WO2013-125798A1
