An electrochemical process implements, in a decoupled manner, a first step of electrolysis of an electrolyte to produce gaseous oxygen in a chamber and a second step of electrochemical conversion of H+ ions into gaseous hydrogen in a chamber which contains a liquid phase and a gas phase not dissolved in the liquid phase. Gaseous hydrogen produced in the conversion step is partly present in the gaseous headspace of chamber and as bubbles in the electrolyte, and partly dissolved in the electrolyte which is saturated with hydrogen. The electrolyte has at least one redox pair (A/B) forming at least one intermediate vector enabling the decoupling of the first and second steps. The interface between the gas and liquid phases is increased during the second step to accelerate the diffusion, from liquid phase to gas phase, of the dissolved hydrogen able to supersaturate the electrolyte. Pressurized gaseous hydrogen is then collected.

The method includes two technological segments (i) a reduction segment and (ii) an oxidation segment that are interconnected by various support technological processes for the regeneration of solutions and gases and heat recuperation. The reduction segment includes an electrolysis that is performed from a solution of chloride salts of an energy carrier. During the electrolysis, these elements reduce to a lower oxidation state, solidify on the electrodes or precipitate to a solid state. The solid substance thus obtained is the energy carrier that can be stored outside of the electrolyser until a need for additional energy emerges. During the electrolysis, chlorine gas develops that is collected and dissolved in water. An HCl solution is regenerated, which is used in the oxidation segment. Oxygen is released in this process. The energy that has thus been stored in the oxidation potential of the energy carrier is released during a spontaneous chemical reaction between the energy carrier and the HCl solution in the oxidation segment. In this chemical reaction, the oxidation state of the chemical elements which constitute the energy carrier is increased to an oxidation state identical to that from before the beginning of the electrolysis. The reaction product hydrogen is formed that represents a high calorific fuel. This fuel can be immediately converted to heat or electrical energy, without a need for intermediate storage, by known methods. Only water enters the entire method, oxygen and hydrogen leave, while the cycle is closed/cyclic for the remaining substances.

A method for preparing an Fe/Ni-free alkali metal hydroxide solution may include electrodepositing Ni ions of an alkali metal hydroxide electrolyte on surfaces of an Au anode and an Au cathode by placing the Au anode and the Au cathode within the Fe-free alkali metal hydroxide electrolyte and applying a voltage in a range of 1.75 to 2.25 between the Au anode and the Au cathode for a period in a range of 8 to 12 hours.

A method for preparing an Fe/Ni-free alkali metal hydroxide solution may include electrodepositing Ni ions of an alkali metal hydroxide electrolyte on surfaces of an Au anode and an Au cathode by placing the Au anode and the Au cathode within the Fe-free alkali metal hydroxide electrolyte and applying a voltage in a range of 1.75 to 2.25 between the Au anode and the Au cathode for a period in a range of 8 to 12 hours.

The present disclosure provides methods and systems for recovering metals from lithium-ion batteries, and specifically to methods and systems for recovering cobalt and nickel jointly in metallic form via electrowinning processes. The present disclosure further provides methods and systems for preparing lithium-ion battery materials for use in metal recovery processes.

The present disclosure provides methods and systems for recovering metals from lithium-ion batteries, and specifically to methods and systems for recovering cobalt and nickel jointly in metallic form via electrowinning processes. The present disclosure further provides methods and systems for preparing lithium-ion battery materials for use in metal recovery processes.

A vapor deposition metal mask substrate includes a nickel-containing metal sheet including a obverse surface and a reverse surface, which is opposite to the obverse surface. At least one of the obverse surface and the reverse surface is a target surface for placing a resist layer. The target surface has a surface roughness Sa of less than or equal to 0.019 m. The target surface has a surface roughness Sz of less than or equal to 0.308 m.

A vapor deposition metal mask substrate includes a nickel-containing metal sheet including a obverse surface and a reverse surface, which is opposite to the obverse surface. At least one of the obverse surface and the reverse surface is a target surface for placing a resist layer. The target surface has a surface roughness Sa of less than or equal to 0.019 m. The target surface has a surface roughness Sz of less than or equal to 0.308 m.

A vapor deposition metal mask substrate includes a nickel-containing metal sheet including a obverse surface and a reverse surface, which is opposite to the obverse surface. At least one of the obverse surface and the reverse surface is a target surface for placing a resist layer. The target surface has a surface roughness Sa of less than or equal to 0.019 m. The target surface has a surface roughness Sz of less than or equal to 0.308 m.

A vapor deposition metal mask substrate includes a nickel-containing metal sheet including a obverse surface and a reverse surface, which is opposite to the obverse surface. At least one of the obverse surface and the reverse surface is a target surface for placing a resist layer. The target surface has a surface roughness Sa of less than or equal to 0.019 m. The target surface has a surface roughness Sz of less than or equal to 0.308 m.