Negative electrode material and preparation method therefor, electrochemical device, and electronic device

An electrochemical device, wherein the electrochemical device comprises a negative electrode plate and an electrolyte, the negative electrode plate comprises a negative electrode current collector and a negative electrode material layer provided on at least one surface of the negative electrode current collector, and the negative electrode material layer comprises a negative electrode material, wherein the negative electrode material comprises silicon-carbon particles, and the silicon-carbon particles include a first region and a second region, the first region is a region extending from the surface of the silicon-carbon particles to a depth of 40 nm from the surface of the silicon-carbon particles;

• the second region is a region extending from a depth of 60 nm from the surface of the silicon-carbon particles to a depth of 100 nm from the surface of the silicon-carbon particles;
• the silicon-carbon particles contains a silicon element and a carbon element;
• based on a total number of atoms of the silicon element and the carbon element in the first region, an atomic percentage of the silicon element in the first region is A %, wherein 19.4≤A≤36.7;
• and
• based on the total number of atoms of the silicon element and the carbon element in the second region, an atomic percentage of the silicon element in the second region is B %, wherein 23.8≤B≤31.8.

An electronic device, wherein the electronic device comprises an electrochemical device, wherein the electrochemical device comprises a negative electrode plate and an electrolyte, the negative electrode plate comprises a negative electrode current collector and a negative electrode material layer provided on at least one surface of the negative electrode current collector, and the negative electrode material layer comprises a negative electrode material, wherein the negative electrode material comprises silicon-carbon particles, and the silicon-carbon particles include a first region and a second region, the first region is a region extending from the surface of the silicon-carbon particles to a depth of 40 nm from the surface of the silicon-carbon particles;

• the second region is a region extending from a depth of 60 nm from the surface of the silicon-carbon particles to a depth of 100 nm from the surface of the silicon-carbon particles;
• the silicon-carbon particles contains a silicon element and a carbon element;
• based on a total number of atoms of the silicon element and the carbon element in the first region, an atomic percentage of the silicon element in the first region is A %, wherein 19.4≤A≤36.7;
• and
• based on the total number of atoms of the silicon element and the carbon element in the second region, an atomic percentage of the silicon element in the second region is B %, wherein 23.8≤B≤31.8.