Composite Negative Electrode Material and Method for Preparing Composite Negative Electrode Material, Negative Electrode Plate of Lithium Ion Secondary Battery, and Lithium Ion Secondary Battery

Abstract

A composite negative electrode material, a method for preparing the composite negative electrode material, a negative electrode plate of a lithium ion secondary battery containing the composite negative electrode material, and a lithium ion secondary battery containing a negative electrode active material of the lithium ion secondary battery, where the composite negative electrode material includes a carbon core and a carbon coating layer, where the carbon coating layer is a carbon layer that coats a surface of the carbon core, and both the carbon core and the carbon coating layer include a doping element, where the doping element is at least one of element N, P, B, S, O, F, Cl, or H.

What is claimed is: 
     
         1 . A composite negative electrode, comprising:
 a carbon core comprising a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen, or pyrrolic nitrogen; and   a carbon coating layer comprising a carbon layer that coats a surface of the carbon core,   wherein the carbon coating layer comprises a second doping element that is Phosphorus (P), Boron (B), Sulfur (S), Oxygen (O), Fluorine (F), Chlorine (Cl), or Hydrogen (H), and   wherein the first doping element is different from the second doping element.   
     
     
         2 . The composite negative electrode of  claim 1 , wherein a mass of the carbon coating layer is 5 percent (%) to 30% of a total mass of the carbon coating layer and the carbon core. 
     
     
         3 . The composite negative electrode of  claim 1 , wherein a mass of the first doping element and the second doping element in the composite negative electrode is 0.1 percent (%) to 50%. 
     
     
         4 . The composite negative electrode of  claim 1 , wherein the carbon core comprises natural graphite. 
     
     
         5 . The composite negative electrode of  claim 1 , wherein the carbon core comprises artificial graphite. 
     
     
         6 . The composite negative electrode of  claim 1 , wherein the carbon core comprises expanded graphite. 
     
     
         7 . The composite negative electrode of  claim 1 , wherein the carbon core comprises graphite oxide. 
     
     
         8 . The composite negative electrode of  claim 1 , wherein the carbon core comprises hard carbon. 
     
     
         9 . The composite negative electrode of  claim 1 , wherein the carbon core comprises soft carbon. 
     
     
         10 . The composite negative electrode of  claim 1 , wherein the carbon core comprises at least one of graphene, carbon nanotube, or carbon fiber. 
     
     
         11 . A negative electrode plate of a lithium ion secondary battery, comprising:
 a current collector; and   a composite negative electrode material that covers the current collector, wherein the composite negative electrode material comprises:
 a carbon core comprising a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen, or pyrrolic nitrogen; and 
 a carbon coating layer comprising a carbon layer that coats a surface of the carbon core, wherein the carbon coating layer comprises a second doping element that is Nitrogen (N), Phosphorus (P), Boron (B), Sulfur (S), Oxygen (O), Fluorine (F), Chlorine (Cl), or Hydrogen (H), and wherein the first doping element is different from the second doping element. 
   
     
     
         12 . The negative electrode plate of  claim 11 , wherein a mass of the carbon coating layer is 5 percent (%) to 30% of a total mass of the carbon coating layer and the carbon core. 
     
     
         13 . The negative electrode plate of  claim 11 , wherein a mass of the first doping element and the second doping element in the composite negative electrode material is 0.1 percent (%) to 50%. 
     
     
         14 . The negative electrode plate of  claim 11 , wherein the carbon core comprises natural graphite. 
     
     
         15 . The negative electrode plate of  claim 11 , wherein the carbon core comprises at least one of graphene, carbon nanotube, or carbon fiber. 
     
     
         16 . A lithium ion secondary battery comprising:
 a negative electrode plate comprising:
 a current collector; and 
 a composite negative electrode material covering the current collector and comprising:
 a carbon core comprising a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen, or pyrrolic nitrogen; and 
 a carbon coating layer comprising a carbon layer that coats a surface of the carbon core, wherein the carbon coating layer comprises a second doping element that is Nitrogen (N), Phosphorus (P), Boron (B), Sulfur (S), Oxygen (O), Fluorine (F), Chlorine (Cl), or Hydrogen (H), and wherein the first doping element is different from the second doping element; 
 
   a positive electrode;   a separator separating the negative electrode plate and positive electrode from each other;   a non-aqueous electrolyte; and   a shell that houses the negative electrode plate, the positive electrode, the separator, and the non-aqueous electrolyte.   
     
     
         17 . The lithium ion secondary battery of  claim 16 , wherein a mass of the carbon coating layer is 5 percent (%) to 30% of a total mass of the carbon coating layer and the carbon core. 
     
     
         18 . The lithium ion secondary battery of  claim 16 , wherein a mass of the first doping element and the second doping element in the composite negative electrode material is 0.1 percent (%) to 50%. 
     
     
         19 . The lithium ion secondary battery of  claim 16 , wherein the carbon core comprises natural graphite. 
     
     
         20 . The lithium ion secondary battery of  claim 16 , wherein the carbon core comprises at least one of graphene, carbon nanotube, or carbon fiber.