Cathode material of lithium ion battery and battery

Abstract

The invention provides a cathode material of a lithium ion battery. The cathode material contains active substance and conductive agent, wherein the conductive agent comprises a first conductive agent and a second conductive agent; the first conductive agent is a conductive polymer containing polar groups, and the second conductive agent is one or more selected from carbon black, graphite, carbon fiber, carbon nanotube, nickel carbonyl powder, copper powder, iron powder, zinc powder and aluminium powder. The invention also provides a lithium ion battery. During a slurry preparation process, polar groups facilitate hydrogen bond formation on the second conductive agent and the anode active substance surface and enhance disperse degree of the second conductive agent and the anode active substance in a solvent, so that the slurry is more easily coated, and the coating thickness is uniform; and the prepared polar sheet has good consistency.

Description

Technical field [0001] The invention relates to a lithium ion battery cathode material and a battery using the cathode material. Background technique [0002] Lithium-ion batteries have the characteristics of high discharge voltage, high energy density, and long cycle life. Therefore, they are widely used in the field of portable electronic devices and are favored by high-tech applications such as military, aerospace, and electric vehicles. [0003] The main performance indicators of lithium-ion batteries include battery capacity and cycle performance. The quality of battery performance depends on the electrode material. A traditional lithium battery is composed of a positive electrode, a negative electrode, a separator and an electrolyte. The lithium ion battery cathode material contains a cathode active material, a conductive agent and a binder. In the preparation process of traditional lithium ion battery electrodes, a certain amount of conductive agents such as carbon black a...

AI Technical Summary

Problems solved by technology

[0005] However, the compatibility of the above-mentioned conductive polymer with the binder and solvent is not high, the construction performance of the slurry is not good, and the thickness of the coated pole piece is uneven, resulting in poor consistency of the prepared batch batteries. Power tools such as electric vehicles use a large number of batteries connected in series and parallel to provide power. The performance of the battery pack is definitely not the algebraic sum of the performance of a single battery.

Small differences between batteries, even slight differences, will cause differences in the capacity, internal resistance and other characteristics of each battery unit, so that the battery with a large capacity will always be in a state of shallow charge and discharge with a small current, while the battery with a small capacity will always be in a state of shallow charging and shallow discharge. In the state of high current overcharge and overdischarge, the difference in performance parameters between the two is getting bigger and bigger, and the one with small capacity will fail early; or the one with large internal resistance will become an energy-consuming series resistor, which is prone to overheating and shortens the life.

During the use of the battery pack, the temperature, voltage, and current of each battery unit are different. After working for a period of time, the consistency of the battery pack will definitely continue to deteriorate, and finally the energy efficiency of the battery will be rapidly reduced to an unacceptable level. Level

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