Negative electrode active material for battery, preparation method of negative electrode active material, electrode and battery

The invention provides a negative electrode active material for a battery, a preparation method of the negative electrode active material, an electrode and the battery. The negative electrode active material comprises negative electrode active material particles; the negative electrode active material particles comprise porous silicon-oxygen compound particles and a carbon film layer, the porous silicon-oxygen compound particles comprise micropores, the pore diameter of the micropores is less than 2nm, the pore volume of the porous silicon-oxygen compound particles is less than or equal to 0.25 cm < 3 >/g, and the surfaces of the porous silicon-oxygen compound particles are partially or completely covered by the carbon film layer. The negative electrode active material for the battery, provided by the invention, has the electrochemical characteristics of high compaction density, small expansion and high energy density during use. The battery prepared from the negative electrode active material has the advanta