Patent ID: 9735418
Date: 2017-08-15
CPC Classifications: C25D,H01M,Y02E

Claim:
1. A method for preparing an anode active material for a lithium secondary battery, the method comprising: dispersing a carbon material in an electroplating electrolyte of an electroplating bath, wherein the electroplating bath includes a main electrode and a counter electrode disposed therein; and then applying an electric current to form a coating layer having a plurality of Sn-based domains having an average diameter of 1 μm or less on the surface of particles of the carbon material, wherein the electric current is a pulse current ranging from 0.1 A to 10 A; and stirring the electrolyte at a speed ranging from 800 to 900 rpm while the electric current is applied, wherein the anode active material comprises the particles of the carbon material having the coating layer formed on the surface thereof, wherein the Sn-based domains have a hemisphere shape and/or agglomeration of several hemispheres, wherein the Sn-based domains are of an Sn alloy and wherein the Sn alloy is an alloy of Sn and a metal selected from the group consisting of Mg, Al, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Pd, Ag, Cd, In, Sb, Pt, Au, Hg, Pb and Bi, and wherein the coating layer has a density of 2.2 to 5.9 g·cm