01/2020 Accepted Article Title: Enhancing performances of Polydopamine as cathode for Lithium- and Potassium-ion batteries by simple grafting of sulfonate groups Authors: Aqil Abdelhafid, Christine Jérôme, Frèdèric Boschini, and Abdelfattah Mahmoud This manuscript has been accepted after peer review and appears as an Accepted Article online prior to editing, proofing, and formal publication of the final Version of Record (VoR). This work is currently citable by using the Digital Object Identifier (DOI) given below. The VoR will be published online in Early View as soon as possible and may be different to this Accepted Article as a result of editing. Readers should obtain the VoR from the journal website shown below when it is published to ensure accuracy of information. The authors are responsible for the content of this Accepted Article. To be cited as: Batteries & Supercaps 10.1002/batt.202000242 Link to VoR: https://doi.org/10.1002/batt.202000242