A neutralization cell is provided which may be used to increase a pH level of a chlorine solution. The neutralization cell includes a neutralization anode, a neutralization cathode, an inlet, and an outlet. The neutralization anode and the neutralization cathode are positioned to divide the neutralization cell into a middle area between the neutralization anode and the neutralization cathode, an anode area on a side of the neutralization anode furthest from the neutralization cathode, and a cathode area on a side of the neutralization cathode furthest from the neutralization anode. The inlet directs the chlorine solution into the neutralization cell by directing an incoming flow of the chlorine solution into the anode area. The outlet directs the chlorine solution out of the neutralization cell by directing an outgoing flow of the chlorine solution from the cathode area.

The invention relates to a method for producing graphene flakes by electrochemical exfoliation, where electrodes (anode and cathode) together with electrolyte constitute an electrochemical circuit with current flowing through it, characterized in that the electrodes are immersed at least partially in the electrolyte and electrolysis is carried out, during which graphene flakes detach from the electrode to be released into the electrolyte solution and then the exfoliated graphene flakes are recovered from the electrolyte solution.

The invention relates to a method for producing graphene flakes by electrochemical exfoliation, where electrodes (anode and cathode) together with electrolyte constitute an electrochemical circuit with current flowing through it, characterized in that the electrodes are immersed at least partially in the electrolyte and electrolysis is carried out, during which graphene flakes detach from the electrode to be released into the electrolyte solution and then the exfoliated graphene flakes are recovered from the electrolyte solution.

There are provided processes for preparing lithium hydroxide that comprise submitting an aqueous composition comprising a lithium compound to an electrolysis or an electrodialysis under conditions suitable for converting at least a portion of the lithium compound into lithium hydroxide. For example, the lithium compound can be lithium sulphate and the aqueous composition can be at least substantially maintained at a pH having a value of about 1 to about 4.

Disclosed herein is an electro-synthesizer unit comprising a first compartment comprising a cathode and a first electrolyte, a second compartment comprising an anode and a second electrolyte and a third compartment comprising a third electrolyte. The unit is configured to produce acid and base solution at desired concentrations. Also disclosed are methods of using the electro-synthesizer unit and producing the acid and base solution at desired concentrations.

Disclosed herein is an electro-synthesizer unit comprising a first compartment comprising a cathode and a first electrolyte, a second compartment comprising an anode and a second electrolyte and a third compartment comprising a third electrolyte. The unit is configured to produce acid and base solution at desired concentrations. Also disclosed are methods of using the electro-synthesizer unit and producing the acid and base solution at desired concentrations.

An electrochemical cell including a first chamber having an anode, a second chamber having a cathode, at least one ionic connection between the first chamber and the second chamber, such that liquid electrolyte from the first chamber is prevented from mixing with liquid electrolyte in the second chamber is provided. The first chamber and the second chamber can be arranged in parallel and positioned remotely from each other. An electrochemical system including the electrochemical cell, and first and second sources of saline aqueous solutions is also provided. Water treatment systems are also provided. A method of operating an electrochemical cell including introducing first and second saline aqueous solutions into first and second chambers of the electrochemical cell, and applying a current across the anode and the cathode to generate first and second products, respectively is also provided. A method of facilitating operation of an electrochemical cell is also provided.

The present disclosure relates to an electrode for CO.sub.2 electroreduction in an acidic electrolyte comprising cation species, the electrode comprising: a substrate, a metal-based catalyst material, and a cation-augmenting material; wherein the cation-augmenting material comprises an acidic group exchanging protons with the cation species of the acidic electrolyte so as to increase a concentration of the cation species at a surface of the electrode.

The present disclosure relates to an electrode for CO.sub.2 electroreduction in an acidic electrolyte comprising cation species, the electrode comprising: a substrate, a metal-based catalyst material, and a cation-augmenting material; wherein the cation-augmenting material comprises an acidic group exchanging protons with the cation species of the acidic electrolyte so as to increase a concentration of the cation species at a surface of the electrode.

The present invention relates to a method for preparing lithium hydroxide, comprising subjecting an aqueous composition (A), comprising lithium sulfate and sodium sulfate, to bipolar membrane electrodialysis; said step of bipolar membrane electrodialysis comprises processing in an electrodialyser comprising at least one electrodialysis cell (200) comprising a first compartment (220), supplied with water and delimited between a first bipolar membrane (250) and an anionic central membrane (230), and a second compartment (210), supplied with said aqueous composition (A) and delimited between said anionic central membrane (230) and a second bipolar membrane (240), then recovering, from said at least one electrodialysis cell (200), an aqueous composition (B) comprising lithium hydroxide and sodium sulfate, and subjecting it to a crystallisation step in order to prepare a salt.