Abstract: A method according to an embodiment is for recovering a valuable metal from a waste electrode material of a lithium secondary battery by using lithium carbonate. An anode-cathode mixed electrode material that has been separated by draining, crushing, screening, and sorting a waste lithium secondary battery is preprocessed. A precipitation operation performed by adding lithium carbonate (Li2CO3) to a metal melt acquired by performing sulfuric acid dissolution using sulfuric acid. A valuable metal such as nickel, cobalt, manganese, aluminum, and copper is recovered as a residue in the form of a carbonate composite, and a lithium sulfate (Li2SO4) aqueous solution including lithium is recovered as a filtrate.

Abstract: This application relates to an electrochromic lens. In one aspect, the lens includes a substrate including a first surface and a second surface opposite to the first surface, a first electrode layer disposed on the first surface of the substrate, and a second electrode layer disposed on the first electrode layer. The lens may also include an electrochromic layer disposed between the first electrode layer and the second electrode layer, and adjusting transmittance of light incident on the second surface of the substrate. The lens may further include a first conductor electrically connected to the first electrode layer, and having higher conductivity than at least one of the first electrode layer or the second electrode layer. The lens may further include a second conductor electrically connected to the second electrode layer, and having higher conductivity than at least one of the first electrode layer or the second electrode layer.