Negative electrode, secondary battery and device comprising same

A negative electrode, comprising:

• a negative electrode current collector;
• a first active material layer close to the negative electrode current collector, the first active material layer comprising a first active material;
• and a second active material layer disposed on a surface of the first active material layer away from the negative electrode current collector, the second active material layer comprising a second active material;
• wherein the first active material and the second active material are independently oval-like particles with through holes and/or blind holes, and the first active material has an average pore size greater than that of the second active material,
• wherein the first active material has an average pore size from 70 to 140 nm, and the second active material has an average pore size from 10 to 30 nm;
• wherein a ratio of short diameter to long diameter of the first active material is from 0.5 to 0.9;
• and a ratio of short diameter to long diameter of the second active material is from 0.3 to 0.8;
• wherein the first active material has a porosity greater than that of the second active material;
• wherein the first active material has a particle size Dv50 from 8 to 18 μm;
• and/or the second active material has a particle size Dv50 from 5 to 15 μm;
• and
• wherein the second active material and the first active material are carbon-based materials.