Lithium-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 makes the sustainable supply of battery raw materials a strategic need [1]. 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 of 372 mAhg- 1, which is insufficient for next-generation LIBs. Even more concerning, it has been listed as a critical raw material by the European Comission [2]. 

In this work, results on the implementation of SiO2-frustules from Asterionella Formosa diatom specie are presented. A. Formosa was cultured in a 20 L photobioreactor under controlled conditions of growing factors. Frustules were harvested and negative electrodes containing 50 % of SiO2 frustules as active material, 35 % of carbon black and 15 % of Na-alginate binder were prepared and assembled in coin cells using Lithium foil as counter electrode. Half-cells were galvanostatically cycled between 2 mV and 2 V, reaching specific capacities of 730 mAhg-1. These results anticipate the great potential of cultivated diatom species for providing high-performance materials for LIB technology.