Logo: to the web site of Uppsala University

The transition to a sustainable society requires not only advances in renewable energy technologies but also the development of environmentally responsible materials from renewable sources. A circular economy depends on the effective use of biomass and biowaste—not only for energy production, but also for functional materials and fine chemicals. Replacing fossil-based carbon with renewable feedstocks reduces environmental impact, decreases reliance on imported resources, and strengthens local economies. It also improves resilience by minimising dependence on critical raw materials from geopolitically sensitive regions. Carbon-based materials are central to energy storage systems such as lithium-ion batteries and supercapacitors, yet their current production often relies on mined graphite and fossil-derived carbon, both linked to ecological and economic concerns. This thesis investigates the sustainable synthesis of hard carbon and graphene-like materials from renewable biomass and industrial biowaste, focusing on their use in electrochemical energy storage. Alongside conventional pyrolysis, a novel method—laser-induced carbonisation—is explored as a fast, localised, and energy-efficient alternative that eliminates the need for inert gases and prolonged heating. Biomass precursors such as tannins, kraft lignin, brewer’s spent grain, nanocellulose–polypyrrole composites, and phenolated organosolv lignin were used. The resulting carbons were extensively characterised and tested in supercapacitors and lithium-ion batteries, showing promising performance. Beyond material development, the thesis emphasises the socioeconomic benefits of integrating renewable carbon sources into energy storage value chains. This shift enhances climate sustainability, economic self-reliance, and energy security. Overall, the findings demonstrate that bio-based carbon materials offer viable, high-performance alternatives to conventional sources, supporting a more circular and sustainable energy future.