A device for preparing pH adjusted electrolyte aqueous solution, comprising: a pH adjustor configured to prepare pH-adjusted electrolyte aqueous solution; a second unit in liquid connection with the pH adjustor and configured to dispense the pH-adjusted electrolyte aqueous solution, wherein the pH adjustor comprises: - an electrolysis cell including an anode and a cathode: said cathode comprising pseudocapacitance material, in operation of the pH adjustor, the pseudocapacitance material gets electrons from the anode and adsorbs cations from the electrolyte aqueous solution by electrochemically reacting with said cations, OH - in the electrolyte aqueous solution are consumed by losing electrons, leaving H + in the electrolyte aqueous solution; or said anode comprises pseudocapacitance material, and in operation of the pH adjustor, the pseudocapacitance material loses electrons and adsorbs anions from the electrolyte aqueous solution by electrochemically reacting with said anions, H + in the electrolyte aqueous solution are consumed at the cathode by getting electrons, leaving OH - in the electrolyte aqueous solution; - a controller configured to control the electrolysis process in the electrolysis cell. a pH adjustor configured to prepare pH-adjusted electrolyte aqueous solution; a second unit in liquid connection with the pH adjustor and configured to dispense the pH-adjusted electrolyte aqueous solution, wherein the pH adjustor comprises: - an electrolysis cell including an anode and a cathode: said cathode comprising pseudocapacitance material, in operation of the pH adjustor, the pseudocapacitance material gets electrons from the anode and adsorbs cations from the electrolyte aqueous solution by electrochemically reacting with said cations, OH - in the electrolyte aqueous solution are consumed by losing electrons, leaving H + in the electrolyte aqueous solution; or said anode comprises pseudocapacitance material, and in operation of the pH adjustor, the pseudocapacitance material loses electrons and adsorbs anions from the electrolyte aqueous solution by electrochemically reacting with said anions, H + in the electrolyte aqueous solution are consumed at the cathode by getting electrons, leaving OH - in the electrolyte aqueous solution; - a controller configured to control the electrolysis process in the electrolysis cell. - an electrolysis cell including an anode and a cathode: said cathode comprising pseudocapacitance material, in operation of the pH adjustor, the pseudocapacitance material gets electrons from the anode and adsorbs cations from the electrolyte aqueous solution by electrochemically reacting with said cations, OH - in the electrolyte aqueous solution are consumed by losing electrons, leaving H + in the electrolyte aqueous solution; or said anode comprises pseudocapacitance material, and in operation of the pH adjustor, the pseudocapacitance material loses electrons and adsorbs anions from the electrolyte aqueous solution by electrochemically reacting with said anions, H + in the electrolyte aqueous solution are consumed at the cathode by getting electrons, leaving OH - in the electrolyte aqueous solution; said cathode comprising pseudocapacitance material, in operation of the pH adjustor, the pseudocapacitance material gets electrons from the anode and adsorbs cations from the electrolyte aqueous solution by electrochemically reacting with said cations, OH - in the electrolyte aqueous solution are consumed by losing electrons, leaving H + in the electrolyte aqueous solution; or said anode comprises pseudocapacitance material, and in operation of the pH adjustor, the pseudocapacitance material loses electrons and adsorbs anions from the electrolyte aqueous solution by electrochemically reacting with said anions, H + in the electrolyte aqueous solution are consumed at the cathode by getting electrons, leaving OH - in the electrolyte aqueous solution; - a controller configured to control the electrolysis process in the electrolysis cell.