Recycling of Spent Lithium‐Ion Batteries into Fluorinated Binder‐Enabled Electrocatalysts for Efficient Hydrogen Generation Systems

ABSTRACT The rapid expansion of lithium‐ion battery (LIB) applications in electric vehicles and electronics has led to growing volumes of spent cathodes, highlighting the urgent need for sustainable recycling and upcycling strategies. In this study, we develop a binder‐engineering approach to upcycle spent LiFePO ₄ (LFP) cathodes into efficient electrocatalysts for the hydrogen evolution reaction (HER) in alkaline media. By incorporating fluorine‐rich Nafion as a functional binder and acetylene black (AB) as a conductive additive, the resulting catalyst‐M12 N‐AB(0.3)/NF‐exhibits significantly enhanced HER activity. It delivers a low overpotential of 205.3 mV at current density of 10 mA cm ⁻² and a Tafel slope of 102 mV dec ⁻¹ , outperforming gelatin‐based analogs (overpotential: 256.1 mV) and most reported waste‐derived HER catalysts. Electrochemical impedance spectroscopy reveals reduced charge transfer resistance and improved ion‐electron transport. The catalyst demonstrates excellent durability over 96 h of continuous operation and 3000 cyclic voltammetry cycles, with performance even improving post‐cycling. Driven by the solar energy, substituting the values, the theoretical energy efficiency was determined to be 𝜂 _{𝑡ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙} with 80.7% which highlights the capability of the recycled LFP‐based electrode to enable sustainable approach for solar‐to‐hydrogen energy conversion from converting spent LIBs.