Producing hierarchical porous carbon monoliths from hydrometallurgical recycling of spent lead acid battery for application in lithium ion batteries

In this paper, an environmentally clean process to recycle the paste from a spent lead acid battery (LAB) is further developed in order to produce a porous carbon anode material for a lithium ion battery (LIB) which is currently under increasing focus as the solution for future energy storage and distribution networks. Using lead citrate from hydrometallurgical leaching of lead paste as a precursor, electrochemically active carbon materials were produced as a new product with hierarchical open sponge-like porosity. It was found that anode materials made from porous carbon by pyrolysing lead citrate at 500 °C, with high micropore (<2 nm) volume (0.0248 cm3 g−1) and BET surface area (138.5 m2 g−1), showed remarkable reversible capacity values beyond intercalation at both low and high current densities. In particular, at the high current density of 5000 mA g−1 (13.4 C, according to the theoretical capacity of 372 mA h g−1), a high discharge capacity of 217 mA h g−1 was maintained even after 200 cycles, which is much superior in comparison with other carbon materials.