Method for preparing aluminum-doped zinc oxide coated lithium-ion battery positive-pole material

Abstract

The invention discloses a method for preparing an aluminum-doped zinc oxide coated lithium-ion battery positive-pole material and belongs to the technical field of lithium-ion battery pole materials and preparation thereof. The method has the following steps of: preparing aluminum-doped zinc sol by adopting a sol-gel method, adding a positive pole material into the aluminum-doped zinc sol, stirring until a solvent in the sol is completely evaporated so as to obtain a black positive pole material of which the surface is coated with a hydrolysis product, and then carrying out high-temperature calcination treatment in an air atmosphere, thereby obtaining the lithium-ion battery positive-pole material of which the surface is coated with aluminum-doped zinc oxide. The preparation method disclosed by the invention is simple in process, convenient to operate, low in cost and little in pollution; and the prepared positive-pole material of which the surface is coated with aluminum-doped zinc oxide has good cycle performance, power multiplying performance, overcharge resistance and thermal stability, and meanwhile, the initial discharge capacity of the positive-pole material is not lowered.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery electrode materials and preparation thereof, and in particular provides an aluminum-doped zinc oxide-coated lithium-ion battery positive electrode material and a preparation method thereof. Background technique [0002] Lithium-ion battery is the leader of new high-energy green battery. It is a new type of secondary battery developed on the basis of lithium battery. Lithium-ion batteries have the advantages of high energy density, high power density, high working voltage, long cycle life, good safety performance, no memory effect, and no pollution. It is currently the most advanced green secondary battery. Since its inception, it has been widely used in portable electronic devices such as mobile communication tools, cameras, and notebook computers, and is gradually applied to vehicles such as electric bicycles and electric vehicles. A lithium-ion battery generally includes a positive ...

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Problems solved by technology

However, the above cathode materials have their own disadvantages: LiCoO 2 The structure is unstable at high potential, and the actual capacity is only half of the theoretical capacity; LiNiO 2 The crystal stability is poor and the cycle performance is seriously insufficient; LiMn 2 o 4 Medium Mn 2+ It is easy to dissolve in the electrolyte and cause rapid capacity decay; LiFePO 4 The poor conductivity of Li makes it difficult to deintercalate lithium ions, while LiNi x co y mn 1-x-y o 2 There are problems of low initial charge and discharge efficiency, structural stability and cycle stability to be improved

Therefore, all electrode materials generally face a common problem: as the number of cycles increases, the charge-discharge capacity and cycle reversibility of the electrode will gradually decay, eventually leading to battery failure and scrapping.

These coatings have significantly improved the cycle performance, rate performance, overcharge resistance and thermal stability of the positive electrode material, but there is a very important disadvantage: the first discharge capacity is reduced

The above-mentioned metal oxides have one thing in common, which is low electrical conductivity, which may be the reason for the decrease in the first discharge capacity of the positive electrode material.

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