Sustainable sources of energy have been identified as a possible way out of today's oil dependency and are being rapidly developed. In contrast, storage of energy to a large extent still relies on heavy metals in batteries. Especially when built from biomass‐derived organics, organic batteries are promising alternatives and pave the way towards truly sustainable energy storage. First described in 2008, research on biomass‐derived electrodes has been taken up by a multitude of researchers worldwide. Nowadays, in principle, electrodes in batteries could be composed of all kinds of carbonized and noncarbonized biomass: On one hand, all kinds of (waste) biomass may be carbonized and used in anodes of lithium‐ or sodium‐ion batteries, cathodes in metal–sulfur or metal–oxygen batteries, or as conductive additives. On the other hand, a plethora of biomolecules, such as quinones, flavins, or carboxylates, contain redox‐active groups that can be used as redox‐active components in electrodes with very little chemical modification. Biomass‐based binders can replace toxic halogenated commercial binders to enable a truly sustainable future of energy storage devices. Besides the electrodes, electrolytes and separators may also be synthesized from biomass. In this Review, recent research progress in this rapidly emerging field is summarized with a focus on potentially fully biowaste‐derived batteries.

Electrochemical energy storage using lignin as a renewable electrode material is a cheap and sustainable approach for future organic batteries. Previous reports mainly focus on lignosulfonates (LS) or composites with conductive polymer additives with inherent problems, such as still expensive monomers. Here, composite electrodes are used from more available Kraft lignin and sustainable conductive carbon. Charge storage is evaluated in terms of electrical double layer storage and redox reactions, aiming at a better understanding of desired lignin properties for electrochemical energy storage. Using unmodified, commercial lignin and high surface area conductive carbon, reasonable capacity of ≈80 mAh g−1 is achieved in samples in which a thin layer of lignin covers the interface of high surface area carbon. Non‐faradaic contribution to charge storage is as large as in comparable pure carbon electrodes, and redox reactions in lignin contribute to additional, faradaic charge storage, significantly enhancing capacity in these systems. Resulting electrodes are cheap, reliable, and stable.

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