“…Lignin has multiple structural features and characteristics, which makes it an ideal precursor of ionomer. Of the plant cell wall polymers, cellulose has been widely explored to make green electron (Zhu et al, 2016 ) or ion-conducting materials (Seo et al, 2009 ; Bayer et al, 2016 ; Zhu et al, 2016 ; Vilela et al, 2019 ). However, lignin has been underutilized as an ionomer and majorly used to synthesize porous carbon (graphene, carbon fiber) (Kontturi, 1988 ; Naseem et al, 2016 ) or charge storage materials (Kontturi, 1988 ) [requiring oxidation of phenol groups of lignin to quinone (Furman and Lonsky, 1988 ; Milczarek and Inganas, 2012 ; Milczarek and Nowicki, 2013 ; Thakur et al, 2014 ; Zhu et al, 2016 ) or mixing with quinone (Furman and Lonsky, 1988 )].…”