Positive electrode additive for lithium secondary battery, positive electrode active material comprising same, positive electrode, and lithium secondary battery
The present disclosure relates to a positive electrode additive for a lithium secondary battery, and a positive electrode active material, a positive electrode and a lithium secondary battery including the same, and in particular, the positive electrode additive represented by Formula 1 is formed on a surface of a carbon material included in the positive electrode active material and is not dissolved in an electrolyte solution, which functions to electrically separate the positive electrode and a negative electrode, and accordingly, battery performance is enhanced by suppressing side reactions in the battery.
1 . A positive electrode additive for a lithium secondary battery represented by the following Formula 1:
wherein, R is a linear alkyl group having 8 to 11 carbon atoms.
2 . A method for preparing the positive electrode additive for the lithium secondary battery of claim 1 , comprising:
reacting (i) benzoperylene or a derivative thereof and (ii) a carbon molecule including an amine group on at least one end.
3 . The method for preparing a positive electrode additive for a lithium secondary battery of claim 2 , wherein the benzoperylene derivative is benzoperylene anhydride (BPA), amine group-containing benzoperylene, or carboxyl group-containing benzoperylene.
4 . The method for preparing a positive electrode additive for a lithium secondary battery of claim 2 , wherein the carbon molecule including an amine group on at least one end is an alkylamine having 8 to 12 carbon atoms.
5 . The method for preparing a positive electrode additive for a lithium secondary battery of claim 2 , wherein the reaction is a dehydration condensation reaction including refluxing at a temperature of 100° C. to 200° C. and then cooling.
6 . A positive electrode active material for a lithium secondary battery, comprising:
a carbon material; and
the positive electrode additive of claim 1 on a surface of the carbon material.
7 . The positive electrode active material for a lithium secondary battery of claim 6 , wherein the carbon material is a porous carbon material, and the positive electrode additive is adsorption-bonded to any one or more of an outer surface and an inner surface of the porous carbon material.
8 . The positive electrode active material for a lithium secondary battery of claim 6 , wherein the positive electrode additive is included in an amount of 1 to 15% by weight based on a total weight of the carbon material and the positive electrode additive.
9 . The positive electrode active material for a lithium secondary battery of claim 6 , further comprising sulfur.
10 . The positive electrode active material for a lithium secondary battery of claim 9 , wherein a weight ratio of the sulfur to the total weight of the carbon material and the positive electrode additive is from 1:1 to 1:0.1.
11 . A positive electrode for a lithium secondary battery, comprising the positive electrode active material of claim 6 .
12 . A lithium secondary battery comprising:
the positive electrode of claim 11 ;
a negative electrode;
a separator interposed therebetween; and
an electrolyte solution.
13 . The lithium secondary battery of claim 12 , wherein the electrolyte solution comprises one or more types of ether-based solvents and carbonate-based solvents.