Methods of forming a cobaltocenium-containing polymer are provided through polymerizing a plurality of cobaltocenium-containing monomers via controlled radical polymerization or controlled ring-opening polymerization. Each cobaltocenium-containing monomer comprises a cobaltocenium moiety covalently connected to a polymerizable group. Cobaltocenium-containing monomers are also provided that include a cobaltocenium moiety covalently connected to a polymerizable group. Cobaltocenium-containing polymers are also generally provided, such as the polymers formed according to any of the methods or from any of the monomers discussed herein. Methods are also generally provided for exchanging an anion associated with a cobaltocenium side group of a cobaltocenium-containing polymer with a new anion.