Secondary battery, multifunctional diaphragm and preparation method

Abstract

The invention discloses a secondary battery, a multifunctional diaphragm and a preparation method. The secondary battery comprises the multifunctional diaphragm, the multifunctional diaphragm is mainly composed of a main conductive agent, an auxiliary conductive agent, an auxiliary agent, a water-retaining agent and a binder, and the multifunctional diaphragm is prepared into a film by adopting a physical rolling method. The multifunctional diaphragm disclosed by the invention can effectively play multiple functions in the secondary battery so as to prolong the cycle life and calendar life of the battery: 1) the problems of deformation, dendritic crystal growth, active substance falling and the like commonly existing in a zinc negative electrode in the secondary battery are inhibited; 2) the multifunctional diaphragm has a conductive characteristic, so that the multifunctional diaphragm can be an extension of a zinc negative electrode, and the area of an effective conductive network of the electrode is increased; 3) the multifunctional diaphragm has strong water-retaining property so as to restrain the problem of serious electrolyte loss generally existing in a battery in a semi-open system, 4) the multifunctional diaphragm can restrain the hydrogen evolution reaction of the battery, and for a zinc-nickel battery, oxygen separated out from the interior of the battery can be effectively compounded so as to prevent excessive oxygen recombination of a negative electrode.

Description

technical field

[0001] The invention belongs to the technical field of battery materials, and in particular relates to a secondary battery, a multifunctional diaphragm and a preparation method. Background technique

[0002] At present, the battery technologies for energy storage applications are mainly lithium batteries and lead-acid batteries. Compared with lithium-ion batteries, which have great safety hazards and high costs, lead-acid batteries, as a representative of water-based batteries, have the advantages of intrinsic safety and low cost. , has been widely used. At present, the separators commonly used in secondary batteries are mainly glass fiber, filter paper and polypropylene separators, but these separators have a single component and can only achieve simple physical insulation of the positive and negative electrodes. At present, research is devoted to improving traditional diaphragms, such as modified diaphragms obtained by modifying phosphate and sulfonate com...

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