Abstract: Disclosed is a negative electrode material and a preparation method therefor. The negative electrode material is a core-shell structure, and comprises a core layer formed by hard carbon, and a first carbonized layer, a carbon powder layer and a second carbonized layer which are sequentially coated at the outer side of the core layer. Further disclosed are a negative electrode plate prepared by the negative electrode material, and a sodium ion battery. The negative electrode material of the present disclosure can effectively improve the conductivity of a hard carbon material, thereby facilitating improvement of the performance such as initial Coulombic efficiency and cycle life of the sodium ion battery.

Abstract: The disclosure relates to the technical field of batteries, and discloses a cathode material and a preparation method thereof, a cathode plate and an O3-type layered sodium ion battery. The chemical formula of the cathode material is NaM1-x-y-zNixFeyMnzO2, wherein M comprises a first metal element, and the first metal element has at least one f electron orbital. Ni, Fe and Mn elements in the cathode material are elements containing a d electron orbital. By doping the element M, on the one hand, the f electron orbital and the d electron orbitals are mutually entangled, properties of the cathode material are synergistically improved, so that the structure and air stability of the material are improved; and on the other hand, interaction of all elements in the material can be facilitated, so that ions can move away from original positions to generate vacancies, ion diffusion channels of sodium ions are enlarged, and the rate capability of the material is improved.

Abstract: A multifunctional device is provided, having vibration and sound generation functions, comprising a housing, a vibration system, a magnetic circuit system and an elastic support which are accommodated inside the housing, wherein the magnetic circuit system is support by the elastic support and is suspended inside the housing; the vibration system comprises a vibration diaphragm and a voice coil coupled to one side of the vibration diaphragm; and wherein the elastic support comprises a first fixing portion, second fixing portion, and a deformation portion which is connected between the first and second fixing portions; an orthographic projection of an outer contour of the elastic support in a vibration direction is in a shape of a polygon defined by straight lines or a geometrical shape defined by straight lines and arc lines; and the first fixing portion and the second fixing portion have a height difference there-between.

Abstract: Disclosed is a vibration loudspeaker, comprising a housing, a back lid matching the housing, and a vibration system and a magnetic circuit system in the housing; the housing and the back lid are both square-shaped structures; the four corners of the square-shaped structure of the housing are provided with a recess, and the four corners of the back lid corresponding to the four corners of the housing are provided with a step, such that the back lid and the housing snap together and fix to each other. The vibration loudspeaker of the present invention effectively enhances the firmness of the fitting between the back lid and the housing, thereby enhancing the overall strength of the vibration loudspeaker product of the present invention. The vibration loudspeaker of the present invention has high overall strength, good reliability, and strong shock resistance.

Abstract: A multifunction apparatus, comprising an outer housing and a vibration system, a magnetic circuit system and an elastic supporting member. The magnetic circuit system is fixed by the elastic supporting member and is suspended inside the outer housing. The vibration circuit system comprises a diaphragm and a voice coil. The elastic support member comprises a first fixing portion and a second fixing portion having different heights, and a deformation portion connected with the first fixing portion and the second fixing portion. An orthographic projection of the elastic supporting member in a vibration direction is a polygon or an oval shape. The first fixing portion or the second fixing portion is located at an edge of the elastic supporting member, and four straight edges of the first fixing portion or the second fixing portion are disposed corresponding to a rectangular bottom wall of the magnetic circuit system or the outer housing.

Abstract: Disclosed is a vibration loudspeaker, comprising a housing, a back lid matching the housing, and a vibration system and a magnetic circuit system in the housing; the housing and the back lid are both square-shaped structures; the four corners of the square-shaped structure of the housing are provided with a recess, and the four corners of the back lid corresponding to the four corners of the housing are provided with a step, such that the back lid and the housing snap together and fix to each other. The vibration loudspeaker of the present invention effectively enhances the firmness of the fitting between the back lid and the housing, thereby enhancing the overall strength of the vibration loudspeaker product of the present invention. The vibration loudspeaker of the present invention has high overall strength, good reliability, and strong shock resistance.