Patterned polypyrrole for reversible zinc anodes via electrochemical additive manufacturing

This investigation addresses the need for surface modification and stabilization of the Zn anode for Zn-ion batteries. The approach is based on the use of the electrochemical additive manufacturing (ECAM) technique, which offers multiple benefits for the stabilization of metallic Zn. ECAM allows controlled electropolymerization of pyrrole on Zn substrates by a meniscus-guided deposition and facilitates the formation of patterned films. Another key advantage of ECAM is the possibility of binder-free processing. It is found that the porosity of polypyrrole deposits is increased due to the resettlement of the meniscus. The patterned electrode exhibits improved cyclic stability and reduced overpotential for Zn2+ stripping//plating processes compared to pristine Zn. The electrochemical tests demonstrate that α-MnO2//Zn cells exhibit a reversible capacity of 131.9 mAh/g at 2C by the implementation of patterned polypyrrole.