Sustainable valorization of cattle manure biowaste into carbon anode materials for lithium-ion batteries

Cattle manure is an abundant livestock waste whose disposal burdens the environment, yet it has rarely been applied to lithium-ion battery anodes. This study converted cattle manure into a hard carbon anode through ZnCl 2 activation and compared it with its non-activated counterpart. Elemental analysis showed that ZnCl 2 volatilized during pyrolysis and left intraparticle micropores, which tripled the specific surface area. These micropores increased the accessible sites for adsorption and pore filling, the main lithium storage mechanism of the carbon, so the manure-derived carbon anode exhibited a better rate capability than commercial graphite. The ZnCl 2 treatment also lowered the mineral content of the resulting carbon, and the remaining minerals are expected to favor a thin, ionically conducting solid electrolyte interphase that supports stable performance over 500 cycles. These findings show that ZnCl 2 activation can upcycle cattle manure into a sustainable anode material.