Design of sustainable cathodes for Li ion batteries : understanding the redox behaviour of guaiacyl and catecholic groups in lithium organic system In recent years people have realised non renewability of our modern society which relays on spending huge amounts of energy mostly produced from fosil fuels such as oil and coal and the shift towards more sustainable energy sources has started. However sustainable sources of energy such as wind solar and hydro energy produce primarily electrical energy and can not just be poured in canister like many fosil fuels creating necessity for rechragable batteries. However modern Li ion batteries are made from toxic heavy metals and sustainable alternatives are needed. Here we show that naturally abundant catecholic and guaiacyl groups can be utilised to replace heavy metals in Li ion batteries. Foremost vanillin a naturally occurring food additive that can be sustainably synthesised from industrial biowaste lignin was utilised to synthesise materials that showed extraordinary performance as cathodes in Li ion batteries. Furthermore behaviour of catecholic and guiacyl groups in Li ion system was compared confirming usability ...