Abstract: The present application relates to a current collector, an electrode plate and a preparation method thereof, an electrode assembly, and a secondary battery. Through holes running through a current collecting body are provided in at least one corner region, so that the electrode assembly formed by winding electrode plates provided with the current collectors may feature the through holes in at least one layer of electrode plate in a bent portion. In this case, during cyclic charging, lithium ions on a convex side and a concave side of the electrode plate may communicate through the through holes, thereby ensuring that intercalated lithium concentrations on two sides of the electrode plate are balanced, reducing the risk of lithium precipitation between the negative electrode plate and the positive electrode plate in the bent portion, and prolonging the service life of the secondary battery.

Abstract: The present disclosure discloses a method for extracting a duckweed turion starch, and belongs to the technical field of agriculture and food. The extraction method of the present disclosure includes the following steps: conducting drying and rehydration on a duckweed turion to obtain a rehydrated turion, soaking the rehydrated turion in a solvent, and then conducting washing and filtration to obtain a decolorized duckweed turion; or conducting beating on a fresh duckweed turion, soaking the fresh duckweed turion in a solvent, and then conducting washing and filtration to obtain a decolorized duckweed turion slurry; and putting the decolorized duckweed turion or the decolorized duckweed turion slurry in a dispersion liquid for extraction at a rotation speed of 6,000-18,000 rpm at 25-50° C. for 5-60 min, and then conducting filtration, centrifugation, washing and drying to obtain the duckweed turion starch.