Nickel-metal hydride battery positive electrode slurry, nickel-metal hydride battery positive electrode plate and nickel-metal hydride battery

Abstract

The invention discloses nickel-metal hydride battery positive electrode slurry, a nickel-metal hydride battery positive electrode plate and a nickel-metal hydride battery. The nickel-metal hydride battery positive electrode slurry comprises a positive electrode active material and an auxiliary agent, wherein the auxiliary agent comprises Welan gum and carboxymethyl cellulose. According to the nickel-metal hydride battery positive electrode slurry provided by the embodiment of the invention, the combination of the Welan gum and carboxymethyl cellulose is used as an auxiliary agent in the positive electrode slurry; the combination of Welan gum and carboxymethyl cellulose has unique rheological property, good water solubility and water resistance and heat and acid-base stability, with an extremely small amount of the combination of Welan gum and carboxymethyl cellulose added, super-strong suspension property can be provided for insoluble solids in an alkaline environment of a nickel-metal hydride battery, and the dosage of additives such as a thickening agent and a binding agent is greatly reduced, so that the utilization rate of the positive electrode active material of the battery is effectively improved, and the cycle life of the battery is effectively prolonged.

Description

technical field [0001] The present application relates to the technical field of nickel-metal hydride batteries, in particular to a positive electrode slurry for a nickel-hydrogen battery, a positive electrode sheet for a nickel-hydrogen battery and a nickel-hydrogen battery. Background technique [0002] Ni-MH battery replaces the negative electrode based on cadmium metal with hydrogen-absorbing negative electrode, which increases the capacity per unit volume and eliminates the toxicity of cadmium metal. Therefore, it is widely used as an environmentally friendly secondary rechargeable battery. The preparation methods of nickel-metal hydride batteries can be divided into dry method and wet method according to the different preparation processes. The wet method has good performance consistency and stability, so the wet method is generally used. The method for preparing the positive electrode of Ni-MH battery by wet process is roughly to mix the positive electrode active mate...

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Problems solved by technology

[0003] At present, the mainstream method of positive electrode wet process is to use polyacrylic acid and hydroxyethyl cellulose as thickeners and binders, although polyacrylic acid combined with hydroxyethyl cellulose can be The slurry provides good suspension, but when the pH value of the slurry is higher, the slurry is easy to settle and forms a stable precipitate, which increases the battery impedance and shortens the battery cycle life; on the other hand, in order to ensure the suspension and rheology , the use of polyacrylic acid and hydroxyethyl cellulose is relatively large, which will increase the electrode impedance and reduce the utilization of positive active materials

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