The invention relates to a method for producing lithium hydroxide (4), in particular highly pure lithium hydroxide, for use in batteries and / or accumulators, from lithium-containing ore and / or mineraland / or from lithium-containing earths (1) by means of a chlor-alkali process. The aim of the invention is to create a solution which, in the case of such a method, increases the extraction rate of highly pure lithium hydroxide in the application of a chlor-alkali process. This aim is achieved in that, in a calcining and leaching step (A), a lithium chloride solution (2) is produced, the lithium-containing ores and / or minerals and / or earths (1) first being roasted, one or more metal chlorides (5) and / or a mixture of metal chlorides (5) being used, and then leached out, water being used, then ahighly pure lithium chloride solution (3) being produced in a subsequent purification step (B), the lithium chloride solution (2) being purified in particular by removing cations, such as sodium, potassium, calcium, magnesium, and / or iron, from the lithium chloride solution (2), and then lithium hydroxide (4), in particular highly pure lithium hydroxide, being produced in a subsequent electrolysis step (C), the highly pure lithium chloride solution (3) being subjected to a membrane electrolysis process, which produces chlorine gas and hydrogen as byproducts.