A sustainable strategy for all-metal recycling from spent nickel metal hydride (Ni-MH) batteries was proposed, where H₂SO₄ and NaOH solutions by the electrolysis of Na₂SO₄ solution were used as the leaching agent and precipitation agent, respectively. The leaching of electrode materials was performed in mild condition, and more than 99% of the rare earths were firstly precipitated at pH 1.0 in the form of double sulphates, which were converted to hydroxides by reacting with NaOH. In the following purification steps, Al³⁺ and Fe³⁺ were deposited at pH 5.5, and Zn²⁺ and Mn²⁺ were extracted by saponified D2EHPA-kerosene from the leaching solution, and two hydroxide byproducts with industrial application were obtained. Ni²⁺ and Co²⁺ were precipitated at pH 9.5 with a total recovery rate of 97.5%. The recovery efficiency of Na₂SO₄ was up to 97% in total. This metal recovery approach produces considerable economic profit, without solid or liquid waste in the closed-loop process.