Lithium ion secondary battery, battery cell and negative pole piece

Abstract

The invention discloses a lithium ion secondary battery, a battery cell and a negative pole piece. The lithium ion secondary battery comprises a battery cell and electrolyte, the battery cell comprises a positive pole piece, an isolating membrane and a negative pole piece, the positive pole piece comprises a positive current collector and a positive active material layer arranged on the surface ofthe positive current collector, and the negative pole piece comprises a negative current collector and a negative active material layer arranged on the surface of the negative current collector, wherein the positive current collector and / or the negative current collector are / is a composite current collector, the composite current collector comprises an organic support layer and a conductive layerarranged on at least one surface of the organic support layer, and the heat conductivity coefficient of the composite current collector is 0.01 W / (m.K) to 10W / (m.K), preferably 0.1 W / (m.K) to 2W / (m.K). The lithium ion secondary battery provided by the invention has the good low-temperature performance.

Description

technical field [0001] The invention belongs to the technical field of electrochemical devices, and in particular relates to a lithium-ion secondary battery, a battery cell and a negative pole piece. Background technique [0002] Lithium-ion secondary batteries have high charge and discharge performance, no memory effect, and are environmentally friendly, and are widely used in electric vehicles and consumer electronics products. However, under low temperature conditions, the kinetic performance of lithium-ion secondary batteries generally deteriorates. In severe cases, lithium deposition at the negative electrode will occur, which greatly affects the electrochemical performance and safety performance of lithium-ion secondary batteries. Contents of the invention [0003] Embodiments of the present invention provide a lithium-ion secondary battery, a battery cell, and a negative pole piece, aiming at improving the low-temperature performance of the lithium-ion secondary bat...

AI Technical Summary

Problems solved by technology

However, under low temperature conditions, the kinetic performance of lithium-ion secondary batteries generally deteriorates. In severe cases, lithium deposition at the negative electrode will occur, which greatly affects the electrochemical performance and safety performance of lithium-ion secondary batteries.

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