Graphite particle composition, manufacturing method thereof, negative electrode and power storage device

PROBLEM TO BE SOLVED: To provide a technology capable of applying cushioning properties to a graphite particle-polymer composite.SOLUTION: A manufacturing method of a graphite particle composition includes an action step of causing a graphite particle, an aromatic monomer vinyl copolymer including a vinyl aromatic monomer unit represented by a formula (1) of (CH-CHX) and a basic monomer unit represented by a formula (2) of (CH-CHX) and a treatment agent represented by a formula (3) of L-R-Lto act (Xin the formula (1) represents a phenyl group, a naphthyl group and an anthracenyl group or a pyrenyl group and these groups may also have substituent groups, Xin the formula n(2) represents organic groups containing N and/or P and these groups may also have substituent groups, R in the formula (3) is an alkyl chain of which the carbon number is equal to or more than 2, Land Lare desorption groups, (n) is 0 or 1, and Land Lmay be the same or may also be different).SELECTED DRAWING: None