Nickel and manganese blended lithium ion battery positive material and preparation method thereof

Abstract

The invention provides a nickel and manganese blended lithium ion battery positive material and a preparation method thereof. The method comprises the following steps: carrying out two-stage roasting on a high-nickel material precursor and a lithium source as raw materials to prepare a high-nickel positive material, and blending the prepared high-nickel positive material with a lithium manganate positive material to prepare the nickel and manganese blended lithium ion battery positive material for a power battery. The prepared positive material has the advantages of high safety and good cycle performances, and the preparation method of the positive material has the advantages of simplicity, easy implementation, wide sources of the raw materials, and low cost.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery cathode materials, in particular to a nickel-manganese blended lithium-ion battery cathode material for power batteries and a preparation method thereof. Background technique [0002] With the shortage of fossil energy and the development of industrialization, the pressure of energy shortage and environmental pollution is becoming more and more serious. It is imperative to find clean energy and develop new energy-saving materials preparation methods. [0003] Since Sony commercialized lithium-ion batteries in 1991, lithium-ion batteries have played an increasingly important role in people's lives. As a new type of green energy, lithium-ion batteries are now widely used in computers, cameras , mobile phones and other electronic products and power vehicles. [0004] The most critical part that affects the performance and safety of lithium-ion batteries is the cathode material used, and ...

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Problems solved by technology

[0009] However, the synthesis conditions of high-nickel materials are harsh, and Ni will inevitably be generated during synthesis. 2+ , while Ni 2+ The polarization ability is small, and it is easy to form a disordered salt structure with high symmetry, so there will be a part of Ni 2+ Distributed in the Li layer, resulting in the phenomenon of lithium ion mixing, and lithium ion mixing will have a negative impact on the first charge and discharge efficiency, reversible capacity, cycle performance and other electrochemical properties of the positive electrode material; moreover, currently synthesized high-nickel materials The high residual alkali content and high pH on the surface lead to undesirable phenomena such as "jelly" in the production of lithium-ion batteries, making it difficult to control the production process of lithium-ion batteries, and the safety performance of high-nickel materials is far lower than that of lithium manganate The safety performance of positive electrode materials; at the same time, there are great hidden dangers in the safety of purely using high-nickel materials as positive electrode materials for lithium-ion batteries. Lithium-ion batteries using it as a positive electrode material are likely to explode at this temperature, posing a threat to the safety of drivers

[0010] In the prior art, there are different cathode materials for lithium-ion batteries prepared for power batteries. For example, Chinese patent CN10420137A discloses a method for preparing a nickel-cobalt lithium manganate composite cathode material, which combines lithium manganate with ternary materials. Under the action of the agent, the nickel-cobalt lithium manganese oxide composite positive electrode material is obtained by sintering at a high temperature of 300-700°C. The product obtained by this method is a coated material, and the use of the binder increases the atomic arrangement in the positive electrode material. The degree of chaos is not conducive to the deintercalation and intercalation of lithium ions between the positive and negative electrode materials, and the cycle performance of the positive electrode material is poor

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