Tungsten-containing Compounds Coated Cathode Materials for Lithium-ion Batteries

With the progress of science and technology, various high-end equipment in the field of national defense and military put forward higher requirements for lithium-ion batteries. It is of great practical significance to seek high-performance lithium-ion batteries. Among them, the performance of cathode materials has become the key factor to limit the further improvement of lithium-ion battery performance. It is very important to find high-performance cathode materials for lithium-ion batteries.

A modification method of tungsten-containing compounds coated cathode materials for lithium-ion batteries has been proposed by some researchers. The specific steps are as follows:

Step 1: Dissolve ammonium metatungstate in deionized water and stir it fully until it is completely dissolved and evenly mixed.

Step 2: The mixed liquid, cathode material precursor and lithium salt were added into the ball mill tank by one-step method. The mixture was milled at 100-600 r/min for 3-10 H.

Steps 3. After vacuum drying of the ball-milled mixture, the temperature of the mixture rises from room temperature to 450-650 ℃ at a rate of 5 ℃/min, prefires at a constant temperature of 450-650 ℃ for 3-6 h, then rises to 800-950 ℃ at a rate of 5 ℃/min, and calcines at a constant temperature of 800-950 ℃ for 10-13 H. Finally, the temperature of the mixture decreases to room temperature at a constant rate of 5 ℃/min. After fully grinding, the lithium ion coated with tungsten compounds is obtained.

Modification of cathode materials for lithium-ion batteries coated with tungsten compounds is an innovative, low-cost and environmentally friendly method. After mixing tungsten compounds with precursors of cathode materials and lithium salts in one step, a uniformly distributed Li₂WO₄ fast ionic conductor coating layer is formed on the surface. The characteristics of fast ionic conductor and the role of the coating layer are discussed. The coating can not only effectively inhibit the side reaction between electrolyte and cathode material, but also inhibit the dissolution of transition metals in the material. It can effectively enhance the stability of the material and the recycling performance at high rate.

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