Negative pole piece with coating layer as well as preparation method and application of negative pole piece

Abstract

The invention discloses a negative pole piece with a coating layer as well as a preparation method and application of the negative pole piece. The negative pole piece comprises a negative current collector, and a negative material layer and the coating layer which are sequentially positioned on the surface of at least one side of the negative current collector, wherein a negative active substancein the negative material layer comprises a silicon oxide molecular sieve, and the coating layer comprises simethicone and lithium salt. According to the invention, the negative electrode material replaces the use of lithium metal by adopting the silicon oxide molecular sieve, the silicon oxide molecular sieve is a porous silicon material, the negative pole piece material is prepared from the material, and the surface of the negative pole piece material is coated with the coating layer made of a special material, so that the internal resistance can be effectively reduced, and the battery performance is improved. Meanwhile, the positive electrode is prepared from a high-nickel ternary nickel-cobalt-manganese material, so that the performance of the solid-state battery can be further improved, and the high-energy-density all-solid-state battery can be obtained.

Description

technical field [0001] The present invention relates to the field of new energy power batteries, in particular to the technical field of all-solid-state batteries, to a negative pole piece with a coating layer, its preparation method and application, in particular to a negative pole piece with a coating layer, its preparation Methods, solid-state battery cells and all-solid-state batteries with high energy density. Background technique [0002] The traditional liquid lithium battery is also vividly called "rocking chair battery" by scientists. The two ends of the rocking chair are the positive and negative poles of the battery, and the electrolyte (liquid) is in the middle. Lithium ions are like excellent athletes, running back and forth at both ends of the rocking chair. During the movement of lithium ions from the positive electrode to the negative electrode and then to the positive electrode, the charging and discharging process of the battery is completed. [0003] The ...

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Problems solved by technology

[0004] However, using lithium metal as the negative electrode of an all-solid-state battery has a large change in electrode volume during the cycle, which will lead to electrode pulverization failure in severe cases, and a significant drop in cycle performance. At the same time, lithium is an active material in the electrode, and the corresponding safety hazards are relatively large. For this reason, some manufacturers of all-solid-state batteries have considered using lithium metal and sulfide together to further improve the performance of all-solid-state batteries.

Due to the relationship between the chemical properties of lithium metal and sulfide itself, direct contact between the two is easy to react, resulting in the formation of a stable substance on the surface of lithium metal that blocks the contact between lithium metal and sulfide, thereby reducing the ion density between lithium metal and sulfide. The transmission efficiency will increase the internal resistance of the battery over time, which will cause the all-solid-state battery to fail

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