153results about How to "Relieve deformation" patented technology

The invention provides a lithium-rich pole piece of a lithium ion battery and a preparation method thereof. The lithium-rich pole piece comprises a current collector, a diaphragm and a porous lithium piece, wherein the diaphragm contains an active material and is formed on the current collector; the diaphragm and the current collector form an initial pole piece; and the porous lithium piece covers the diaphragm, and the capacity of the porous lithium piece is matched with the capacity of lithium added to the anode. The preparation method comprises the following steps of: preparing a slurry from the active material, a conductive agent, an adhesive and a solvent, and then applying the slurry on the current collector and drying to obtain the initial pole piece, so that the slurry applied on the current collector becomes the diaphragm after being dried; punching a metal lithium piece to obtain the porous lithium piece, so that the capacity of the porous lithium piece is matched with the capacity of lithium added to the anode; and covering the diaphragm surface of the initial pole piece with the porous lithium piece, to obtain the lithium-rich pole piece of the lithium ion battery. According to the invention, the lithium amount added to the anode can be precisely controlled, the lithium adding uniformity is increased, the first coulombic efficiency, the energy density and the electrochemical properties of the battery are increased, battery deformation is alleviated, the process is simple, and the cost is low.

The invention belongs to the technical field of lithium ion batteries, in particular relates to a composite anode material for the lithium ion battery. The composite anode material comprises an anode active substance and a coating layer coated on the surface of the anode active substance, wherein the anode active substance can be Si, SiOx or silicon alloy, the coating layer is polymer which is of a reticular structure, and the mass percent of the coating layer accounts for 1-20% of the anode material. Compared with the prior art, the composite anode material has the advantages that the polymer which is of the reticular structure and used as the coating layer is coated on the surface of the active substance in a cross-linking manner, the coating layer has the electron conduction property and the ion conduction property, so that the situation that the lithium ions can be inserted into and separated from the anode active substance particles smoothly is ensured; furthermore, the coating layer is of the reticular structure and has good mechanical strength, and therefore, the integrality of the anode active substance particles can be kept in the electrochemical cycle process, the deformation of an anode strip is relieved, the electrochemical cycle performance of the lithium ion battery is improved and the service life of the lithium ion battery is prolonged.