Abstract: A lithium-ion rechargeable battery negative electrode active material and a preparation method thereof, a lithium-ion rechargeable battery negative electrode plate, and a lithium-ion rechargeable battery are disclosed. The negative electrode active material includes a carbon core and a coating layer formed on a surface of the carbon core, a material of the coating layer includes amorphous carbon and a doping element, and the doping element includes element nitrogen. The lithium-ion rechargeable battery negative electrode active material has the carbon core, and the coating layer that includes the doping element and the amorphous carbon is provided on the surface of the carbon core.

Abstract: An organic solar cell device is provided, including a first electrode, a photoactive layer, a hole transport layer, and a second electrode that are stacked successively. The photoactive layer includes an electron receptor material and an electron donor material. The electron receptor material is graphene nitride that forms a foamy film on the first electrode and has a three-dimensional network structure. A part of the electron donor material permeates into the graphene nitride, and a part of the electron donor material is enriched on a side of the hole transport layer to form an electron donor enriched layer.

Abstract: A composite negative electrode material, a method for preparing the composite negative electrode material, a negative electrode plate of a lithium ion secondary battery containing the composite negative electrode material, and a lithium ion secondary battery containing a negative electrode active material of the lithium ion secondary battery, where the composite negative electrode material includes a carbon core and a carbon coating layer, where the carbon coating layer is a carbon layer that coats a surface of the carbon core, and both the carbon core and the carbon coating layer include a doping element, where the doping element is at least one of element N, P, B, S, O, F, Cl, or H.

Abstract: Embodiments of the present invention provide a cathode active material for a lithium-ion secondary battery, where the cathode active material for a lithium-ion secondary battery includes a silicon-based active substance and a nitrogen-doped carbon material. The silicon-based active substance is encased in the interior of the nitrogen-doped carbon material, and the silicon-based active substance is one or more of a nanoparticle and a nanowire; a micropore is arranged on at least one of the exterior and the interior of the nitrogen-doped carbon material; and a material of the nitrogen-doped carbon material is a nitrogen-doped carbon network. The cathode active material for a lithium-ion secondary battery solves a problem in the prior art that a silicon material, when used as a cathode active material, easily falls from a current collector due to a great volume change and has a low conductivity.