Lithium battery positive electrode current collector, preparation method thereof, lithium battery and positive electrode thereof

Abstract

The invention relates to the field of lithium batteries, in particular to a lithium battery positive electrode current collector, a preparation method thereof, a lithium battery and a positive electrode thereof. The positive electrode current collector comprises a polymer film, aluminum metal areas are arranged on the side faces of the two sides of the polymer film, aluminum metal layers are arranged on the aluminum metal areas, and the area of the aluminum metal layers is 40-70% of the area of the polymer film. The lithium battery provided by the invention adopts the positive electrode current collector, so that the energy density of the lithium metal battery is improved, the stripping and falling probability of the positive electrode active material is also reduced in the charging and discharging processes of the battery, the cycle life of the battery is further prolonged, in addition, the condition of micro short circuit of the lithium battery is further reduced, and the safety performance of the lithium battery is improved.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a lithium battery cathode current collector and a preparation method thereof, and a lithium battery and the cathode thereof. 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 a lithium battery is to charge and discharge the battery by intercalating and deintercalating lithium ions back and forth between the positive and negative electrodes. Since the active materials used in the positive and negative electrodes of the battery have poor conductivity, it is necessary to install a current collector on the electrodes to collect the current generated by the active materials and improve the conductivity of the electrodes. ...

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.

Images