Scalable Sustainable Anodes for Li-ion Batteries by Structural Design (SUSTBATT)

SUSTBATT aims to develop Li-ion batteries from affordable, non-toxic and naturally abundant sources. Due to their potential to contribute to zero-emission mobility and storage of renewable energy, Lithium-ion batteries are a technological pathway to climate-change mitigation and energy sustainability. To achieve this, sustainability of battery raw materials is a must. SUSTBATT aims to produce scalable and sustainable high-capacity anodes for Li-ion batteries through the cultivation of diatoms, a type of photosynthetic algae that synthesize hierarchical nanostructured SiO2 skeletons through biomineralization. By tailoring the chemical and structural properties of the diatom frustules, we aim to reach high storage capacities after prolonged cycling. This will pave the way for the innovative integration of sustainably sourced feedstock into the battery technology.

Li-ion batteries (LIBs) can bridge renewable energy sources to power demand and are therefore crucial in achieving energy sustainability. However, the magnitude of the forthcoming market demand for LIBs along with the need for a climate neutral economy means that a sustainable supply of battery raw materials becomes strategically essential. Apart from lithium, there is one material that is a fundamental part of all LIBs: graphite, which is the primary component of LIBs anodes. Graphite exhibits a storage capacity of 372 mAhg-1, which is insufficient for next-generation LIBs. Even more concerning, it has been listed as a critical raw material. SUSTBATT aims to develop scalable high-performance anodes for LIBs from affordable, non-toxic and naturally abundant sources. These constitute an essential prerequisite for reaching true energy sustainability. Recent reports have demonstrated the feasibility of using naturally abundant nanostructured diatom frustules, the major natural source of SiO2, for fabricating LIBs anodes. A landmark of 840 mAhg-1 stable storage capacity after 100 cycles at 100 mAg-1 was achieved by using SiO2 from diatom feedstocks, and a superior landmark of 1100 mAhg-1 at 700 mAg-1 (though with poorer cycling stability) was reached using diatom-derived Si anodes. These findings provoke the need to explore diatom-derived SiOx (0=x=2) structures. The joint competence of the SUSTBATT Consortium will enable the development of scalable and sustainable SiOx anodes that can out-perform current state-of-the-art negative electrodes, paving the way for the innovative integration of natural feedstock into industrial battery production schemes.