Low-temperature high-power lithium-manganese battery and preparation method thereof

Abstract

The invention discloses a low-temperature high-power lithium-manganese battery and a preparation method thereof, the low-temperature high-power lithium-manganese battery is applied to a temperature environment of -40 DEG C, and the discharge current is greater than 3C. The lithium-manganese battery comprises a positive plate, a negative plate, a ceramic diaphragm, an electrolyte and a battery shell, wherein the positive plate, the ceramic diaphragm, the negative plate and the ceramic diaphragm are sequentially and repeatedly laminated to form a dry cell; the lithium-manganese battery is prepared by putting a dry battery cell into a battery shell, injecting an electrolyte, ageing, sealing and ageing, the positive plate and the negative plate are respectively a graphene-based manganese dioxide positive plate and a lithium-carbon composite negative plate, and positive plate reserved tabs are arranged on the front surface and the back surface of the positive plate; and the front and back surfaces of the negative plate are provided with negative plate reserved tabs. According to the present invention, with the application of the optimal material and the optimal process technology, the beneficial effects are completely explained, the high-power discharge performance of the battery in the ultra-low temperature environment is effectively improved, and the lithium ion battery is suitable for the application in the fields of power consumption type electronic digital, special exploration, starting power supplies, military equipment power supplies and the like.

Description

Technical field: [0001] The invention relates to the technical field of a power primary lithium battery, in particular to a low-temperature high-power lithium-manganese battery and a preparation method thereof. Background technique: [0002] Due to its high voltage platform, high energy density, low self-discharge rate and long storage time, lithium-manganese batteries are more and more widely used in the market, and they are used in -40℃ ultra-low temperature environment Consumable electronic digital, special exploration, start-up power supply and military equipment power supply and other special fields are difficult to meet the needs of high-current discharge, especially difficult to meet the rate discharge performance above 3C. [0003] The key to realize the large-rate discharge of primary lithium-manganese batteries in low temperature environment is to improve the discharge performance of primary lithium-manganese batteries. The main factors affecting the discharge perf...

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Problems solved by technology

[0002] Due to its high voltage platform, high energy density, low self-discharge rate and long storage time, lithium-manganese batteries are more and more widely used in the market, and they are used in -40℃ ultra-low temperature environment Consumable electronic digital, special exploration, start-up power supply and military equipment power supply and other special fields are difficult to meet the needs of high-current discharge, especially difficult to meet the rate discharge performance above 3C

[0003] The key to realize the large-rate discharge of primary lithium-manganese batteries in low temperature environment is to improve the discharge performance of primary lithium-manganese batteries. The main factors affecting the discharge performance of primary lithium-manganese batteries lie in the following aspects: 1. Traditional positive electrode materials: electrolytic dioxide Manganese is difficult to meet the high-rate discharge requirements in a low-temperature environment. Secondly, when preparing positive electrodes in the prior art, most of them choose to extrude paste-like electrolytic manganese dioxide on the current collector to form a positive electrode coating, and the positive electrode coating is on the current collector. Relatively fluffy, low density, and the contact surface between manganese dioxide particles and the current collector is small, the internal resistance increases, which affects the discharge characteristics of the primary lithium-manganese battery. 2. The traditional metal lithium strip is used as the negative electrode material of the lithium-manganese battery. On the one hand, the material properties of the metal lithium ribbon are soft, and when the metal lithium ribbon is processed as a negative electrode, it is easy to be wrinkled or broken by the external force; on the other hand, the chemical properties of the metal lithium ribbon are relatively active, and the metal lithium ribbon When it is processed as a negative electrode sheet, it is easy to produce a chemical reaction with moisture in the preparation environment, resulting in a reduction in the electrochemical performance of the negative electrode sheet; The matching is low, which leads to poor fluidity of the electrolyte in the battery, reduces the flexibility of LI+ migration in the electrolyte, and affects the ion conductivity and point transmission rate of the battery in a low temperature environment. 4. In the prior art, the positive plate and When the negative electrode is connected to the external current collector, most of the external tabs are welded, and the internal resistance of the battery is relatively high.

[0004] In addition, the quality of a primary lithium-manganese battery is closely related to the environment in which the battery is prepared, and the high-rate discharge of a primary lithium-manganese battery in a low-temperature environment requires relatively high quality requirements for the battery. In the traditional lithium-manganese battery preparation process, to prepare Take the negative electrode sheet of lithium-manganese battery as an example. Due to the relatively active chemical properties of metal lithium strips, when metal lithium strips are processed as negative electrodes, there are relatively strict controls from the operating environment of employees in the workshop to the processing environment of negative electrode materials inside the equipment. Requirements, in order to meet the quality requirements of lithium-manganese batteries, but this method greatly increases the control cost of the battery preparation environment

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