A lithium battery positive electrode current collector and preparation method thereof, and lithium battery and its positive electrode

Abstract

The invention relates to the field of lithium batteries, in particular to a lithium battery positive electrode current collector and a preparation method thereof, as well as a lithium battery and its positive electrode. The positive electrode current collector includes a polymer film, an aluminum metal area is arranged on both sides of the polymer film, an aluminum metal layer is arranged on the aluminum metal area, and the area of ​​the aluminum metal layer is the area of ​​the polymer film. 40 to 70%. The lithium battery of the present application adopts the above-mentioned positive electrode current collector, which improves the energy density of the lithium metal battery, and at the same time reduces the probability of peeling off of the positive electrode active material during the charging and discharging process of the battery, thereby improving the cycle life of the battery, and further reducing the It avoids the micro-short circuit of the lithium battery and improves the safety performance of the lithium battery.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a lithium battery positive electrode current collector and a preparation method thereof, as well as a lithium battery and its positive electrode. Background technique [0002] Lithium batteries are generally divided into lithium ion batteries and lithium metal batteries, and their components include a positive electrode, a negative electrode, and a current collector corresponding to the positive electrode and the negative electrode. The working principle of the lithium battery is to realize the charging and discharging of the battery through the intercalation and deintercalation of lithium ions between the positive and negative electrodes. Since the active materials used in the positive and negative electrodes of the battery have poor conductivity, a current collector needs to be arranged on the electrodes to collect the current generated by the active materials and improve the c...

AI Technical Summary

Problems solved by technology

[0004] However, in the process of charging and discharging, the positive electrode active material will produce a certain volume deformation, and the volume deformation will lead to the generation of stress, which will cause the peeling off of the positive electrode active material, resulting in a decrease in the cycle life of the battery.

The expansion and contraction of the positive electrode will affect the interfacial contact performance between the positive electrode and the electrolyte layer, resulting in a decrease in cycle performance

In addition, when the battery is internally short-circuited, the short-circuit situation between the negative electrode material and the positive electrode current collector aluminum foil is the most dangerous. Due to the small resistance, large short-circuit current, and unfavorable heat dissipation, thermal runaway is most likely to occur in this situation.

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