Lithium ion battery

Abstract

The invention discloses a lithium ion battery, and relates to the technical field of battery energy storage. The lithium ion battery comprises a metal shell, a cover plate and a columnar roll core arranged in the metal shell; the columnar roll core comprises a positive electrode plate, a negative electrode plate and an isolation membrane; the positive electrode plate comprises a positive electrode paste coating region and a positive electrode current collector exposure region; the negative electrode plate comprises a negative electrode paste coating region and a negative electrode current collector exposure region; the overlaid parts of the positive electrode plate and the negative electrode plate are isolated through the isolation membrane; the width of the isolation membrane is less than the height of the columnar roll core; a positive electrode confluence plate and an insulating confluence plate fixing frame are arranged below the cover plate; the confluence plate fixing frame comprises a side edge insulating part which is sleeved outside the positive electrode confluence plate and the exposed positive electrode current collector; and after the lithium ion battery is assembled, the parts tightly prop against together through extrusion force, so that physical switch-on can be realized through a non-welding manner. The lithium ion battery does not comprise a tab as the conventional battery, and the interior of the cell has no welding point, so that the battery is high in consistency and high high-rate charging and discharging performance and battery energy density can be obtained.

Description

technical field [0001] The invention relates to the technical field of battery energy storage, in particular to a lithium ion battery. Background technique [0002] With the development of mobile electrical equipment and energy storage products, secondary lithium batteries are gradually recognized by the market as a representative of high-energy-density batteries. The common shapes of lithium-ion batteries are mainly cylindrical and square. [0003] The internal structure of the traditional cylindrical secondary lithium battery is as follows: firstly, the winding core is made, and the winding core is formed by winding a layer of positive electrode sheet, a layer of separator, a layer of negative electrode sheet, and a layer of separator film, and the positive electrode sheet and the negative electrode sheet Both include a current collector made of conductive material (the current collector of the positive pole is called the positive current collector, and the current collect...

AI Technical Summary

Problems solved by technology

[0005] 1. During the production process of traditional battery pole pieces, it is necessary to consider the reservation of the welding position between the tab and the pole piece, which requires intermittent coating on the current collector. Intermittent coating of the pole piece will reduce the coating speed, which is not conducive to the release of production capacity; In addition, the scraping method after continuous coating also faces the problems of low production efficiency, secondary pollution of pole pieces and insulation of tabs

[0006] 2. Intermittent coating will cause fluctuations in coating surface density and increase the risk of battery capacity differentiation

[0007] 3. There is a risk of insufficient stability in multi-pole welding, which may easily cause fluctuations in the internal resistance of the battery

[0008] However, the single lug design of the positive and negative electrodes is not conducive to the realization of high power output or input of the battery; the multi-lug design has problems such as difficulty in aligning the tabs, difficulty in insulating the tabs, and the multi-lug battery core tends to be elliptical.

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