Graphene powder, method for producing graphene powder and electrode for lithium ion battery containing graphene powder
In order to prepare a highly conductive and highly dispersible graphene powder and to obtain an electrode for a lithium ion battery with excellent performance utilizing the highly conductive and highly dispersible graphene, a graphene powder and a preparation method thereof is provided. The graphene powder comprises a compound having a catechol group adsorbing on the surface of graphene in a weight ratio of 5-50% relative to the grapheme and the element ratio of oxygen to carbon in the graphene powder measured by X-ray photoelectron spectroscopy is 0.06 or more and 0.20 or less. The method for producing a graphene powder comprise the step of reducing a graphite oxide with a reducing agent having no catechol group in the presence of a compound having a catechol group.
1. A graphene powder comprising graphene and a compound having a catechol group adsorbed on the graphene in a weight ratio of 5% or more and 50% or less relative to the graphene, and an element ratio of oxygen to carbon in the graphene powder measured by X-ray photoelectron spectroscopy is 0.06 or more and 0.20 or less.
2. The graphene powder according to claim 1 , wherein the compound is selected from the group consisting of catechol, dopamine hydrochloride, dopa, noradrenalin, 3,4-dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, caffeic acid, 4-methylcatechol, 4-tert-butylpyrocatechol, and combinations thereof.
3. The graphene powder according to claim 2 , wherein the compound is selected from the group consisting of dopamine hydrochloride and dopa.
4. The graphene powder according to claim 3 , wherein an element ratio of nitrogen to carbon measured by X-ray photoelectron spectroscopy is 0.005 or more and 0.02 or less.
5. A lithium ion battery electrode, comprising the graphene powder according to claim 1 , an electrode active material and a binder.
6. A lithium ion battery electrode, comprising the graphene powder according to claim 2 , an electrode active material and a binder.
7. A lithium ion battery electrode, comprising the graphene powder according to claim 3 , an electrode active material and a binder.
8. A lithium ion battery electrode, comprising the graphene powder according to claim 4 , an electrode active material and a binder.
9. The graphene powder of claim 1 , wherein the graphene powder has good dispersibility in a solution of 1 part by weight of the graphene powder in 99 parts by weight of N-methylpyrrolidone, wherein the solution is subjected to ultrasonification for 30 minutes, and wherein the good dispersibility means that the solution after the ultrasonification is in a state of being visually homogeneous.
10. A graphene powder comprising graphene and a compound adsorbed on the graphene in a weight ratio of 5% or more and 50% or less relative to the graphene, wherein the compound has a structure in which a portion or all of the 3-position to 6-position of 1,2-benzendiol are modified, and an element ratio of oxygen to carbon in the graphene powder measured by X-ray photoelectron spectroscopy is 0.06 or more and 0.20 or less.