Aqueous lithium ion battery electrode, preparation method of electrode and aqueous lithium ion battery

Abstract

The invention discloses an aqueous lithium ion battery electrode, a preparation method of the electrode and an aqueous lithium ion battery. The aqueous lithium ion battery electrode comprises a positive electrode current collector or a negative electrode current collector, a positive electrode active material layer or a negative electrode active material layer and protective layers, wherein the positive electrode active material layer is combined on the surface of the positive electrode current collector; the negative electrode active material layer is combined on the surface of the negative electrode current collector; the protective layers are combined on the surface of the positive electrode active material layer or the negative electrode active material layer and hole walls in the positive electrode active material layer and the negative electrode active material layer. Materials adopted by the protective layers are polymers containing lithium ions. Through the aqueous lithium ion battery electrode, the direct contact between the positive electrode active material layer or the negative electrode active material layer and water of an aqueous electrolyte can be prevented, so that hydrogen evolution reaction and oxygen evolution reaction of the aqueous electrolyte can be prevented, thus side reaction between active substances and water can be prevented. The aqueous lithium ion battery comprises a positive aqueous lithium ion battery electrode and a negative aqueous lithium ion battery electrode, thus giving high voltage and energy density to the aqueous lithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of batteries, and in particular relates to an electrode of an aqueous lithium ion battery, a preparation method thereof, and an aqueous lithium ion battery. Background technique [0002] With the low-carbon economy in the ascendant, lithium-ion batteries are actively developing in the direction of power vehicles and grid energy storage. The development of lithium-ion batteries with high energy density, long cycle life, high safety and low cost has become the focus of industry research. [0003] The current organic solvent system lithium-ion battery has the characteristics of high voltage, high energy density, and good cycle performance. It is widely used in portable digital products, such as mobile phones, cameras, and notebook computers. At the same time, it has gradually begun to be used in the field of electric bicycles. However, because the battery uses organic solvents, the safety of the battery has alw...

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Problems solved by technology

[0007] However, this aqueous lithium-ion battery has the following defects: in aqueous solution, when the lithium ion intercalation and deintercalation process reaches a certain potential, hydrogen evolution and oxygen evolution reactions will occur, and it is difficult to find lithium ion intercalation and deintercalation without hydrogen evolution. , oxygen-evolving electrode materials, and the negative electrode materials used have poor cycle performance

[0009] However, this water-based lithium-ion battery also has the following defects: the use of LiTi 2 (PO4) 3 As a negative electrode, the gram capacity is low (about 100mAh / g), and the potential for lithium is high (about 2.5V), resulting in a low battery operating voltage, less than 2.0V. The energy density of such an aqueous lithium-ion battery is only about 40Wh / Kg. Therefore, Limits the application, such as not being able to be applied to electric vehicles, and the positive active material is in contact with water, resulting in poor cycle performance

[0011] However, this water-based lithium-ion battery still has the following defects: in an actual battery, it is difficult to completely separate the solution system on both sides of the positive and negative sides.

[0012] From the above, the electrolyte solvent water in the current water-based lithium-ion battery is due to its decomposition potential, especially the reduction potential of hydrogen is high relative to the lithium potential. Low, generally the voltage range is only between 0.8 ~ 1.5V, the low voltage makes the energy density of the battery low, it is difficult to be applied

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