This application provides a battery current collector and a preparation method thereof, a secondary battery, a battery module, a battery pack, and an electric apparatus. The battery current collector includes a foam metal layer (1) and a strength enhancement layer (2), where the strength enhancement layer (2) is a sheet-shaped metal layer, and the strength enhancement layer (2) and the foam metal layer (1) are stacked and metallurgically bonded, alleviating a problem of poor mechanical performance of current collectors in the related art. The strength enhancement layer (2) and the foam metal layer (1) are connected by metallurgical bonding, which helps ensure not only structural strength of the strength enhancement layer (2) and the foam metal layer (1), but also good conductivity between the strength enhancement layer (2) and the foam metal layer (1). Further, the manner of metallurgical bonding helps reduce production costs.

A method for preparing a porous metal material comprises: in a vacuum environment, volatilizing one or more volatile alloy elements in an alloy, so as to finally form a porous pure metal or a porous alloy. The process method can be widely applied in the fields such as aeronautics and astronautics, atomic energy, electrochemistry, petrochemical industry, metallurgy, machinery, medicines, environmental protection or construction.

A porous magnesium structure for storing hydrogen comprising a magnesium skeleton and pores, having a three-dimensional porous structure, wherein the average thickness of the magnesium skeleton is greater than 0 nm and less than or equal to 200 nm, a method of preparing same, and a method of storing hydrogen, are provided.

A porous metal structure and a preparation method for the same. The preparation method for the porous metal structure includes the following steps: performing first de-alloying treatment on an alloy foil to form pores, then performing reduction annealing treatment in a reducing gas atmosphere, and finally performing second de-alloying treatment to obtain the porous metal structure.