In Situ Self-Assembled La and Y Nanoparticles Based on Biomineralization of Diatom Frustules to Boost the Electrochemical Performance of SiO2 Anodes for Lithium-Ion Batteries

Using diatoms, a typical microbial system of biomineralization, as a template, La₂O₃ and Y₂O₃ are synthesized in situ via biological self-assembly during the cultivation of diatoms in La³⁺/Y³⁺-containing media without any supplements, reducing agents or triggering agents. Then, diatom frustules modified with La and Y nanoparticles (NPs) are prepared via high-temperature reduction and crystallization. Furthermore, it has been used as an anode material for lithium-ion batteries and has excellent electrochemical properties. The DFT calculations reveal that the doping of La and Y changes the energy band structure near the Fermi level of SiO₂ and increases the current carrying density. The diatom frustule SiO₂ anodes loaded with La and Y nanoparticles (DBS@C-La-10 and DBS@C-Y-10) have specific discharge capacities of approximately 1021.3 and 980.7 mAh g⁻¹, respectively, after 220 cycles. This is the first study in which the mineralization behavior of rare earth elements on diatom frustules is reported and applied to anodes in lithium-ion batteries. This work provides a new option for applying rare earth elements in the field of energy storage.