Abstract: Provided are electrochemical cells, comprising water-retaining components, and methods of fabricating such electrochemical cells. A water-retaining component is configured to deliver water to the positive active material during the operation of the electrochemical cell. The water-retaining component may be a part of the positive active material layer, a part of the electrolyte layer, and/or a standalone component. In some examples, the water-retaining component comprises one or more crystal hydrates (e.g., MgSO4, MgCl2, Na2SO4, Na2HPO4, CuSO4, CaCl2, KAl(SO4)2, and Mg(NO3)2), one or more water-retaining polymers (e.g., sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, and a cellulose derivative), one or more inorganic compounds (e.g., fumed silica, precipitated silica). In some examples, a method of forming an electrochemical cell comprises printing a positive active material layer, a negative active material layer, and an electrolyte layer, e.g.

Abstract: Provided are printed electrochemical cells, which utilize zinc salts for ionic transfer, and methods of fabricating such cells. In some examples, a printed electrochemical cell comprises a positive electrode with a positive current collector having a two-dimensional shape and comprising an electrolyte-facing surface formed by the graphite. For example, the positive current collector may be a graphite foil or an aluminum foil with a graphite coating. The cell also comprises electrolyte comprising an electrolyte salt and an electrolyte solvent. For example, the electrolyte salt comprises a zinc salt with a concentration of at least 30% by weight in the electrolyte. The cell is fabricated by printing a positive active material layer over the positive current collector, printing one or more electrolyte layers on various cell components, and laminating a separator layer between the positive and negative electrodes while soaking the separator layer with the electrolyte.