Lithium-ion secondary batteries, batteries and negative electrodes

Abstract

The invention discloses a lithium-ion secondary battery, a battery cell and a negative pole piece. The lithium-ion secondary battery includes a battery core and an electrolyte solution. The battery core includes a positive pole piece, a separator and a negative pole piece. The positive pole piece includes a positive pole A current collector and a positive active material layer disposed on the surface of the positive current collector, and the negative electrode sheet includes a negative current collector and a negative active material layer disposed on the surface of the negative current collector; wherein the positive current collector and / or the negative current collector are composite current collectors The composite current collector includes an organic support layer and a conductive layer disposed on at least one surface of the organic support layer, and the thermal conductivity of the composite current collector is 0.01W / (m·K)~10W / (m·K), preferably 0.1 W / (m·K)~2W / (m·K). The lithium ion secondary battery provided by the invention has 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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