Vanadium oxides have attracted extensive attention as cathode materials for calcium-ion batteries (CIBs) because of their intrinsic advantages of high theoretical capacity and cost-effectiveness. However, the intercalation of Ca2+ into the vanadium oxide framework faces critical challenges associated with significant volume change and sluggish ionic diffusion kinetics arising from the large ionic radius of Ca2+, resulting in poor cycling stability and inferior rate capability. To address these bottlenecks, an organic molecule preintercalation strategy is proposed to tailor the interlayer structure of V2O5. Anthraquinone (AQ) molecule intercalation not only remarkably enlarges the interlayer spacing to facilitate Ca2+ migration and serves as structural pillars to enhance framework stability but also enables AQ molecules to participate in redox reactions, thereby yielding additional capacity. Benefiting from these synergistic merits, AQ-intercalated V2O5 (AQ0.1VO) delivers outstanding long-term cycling stability over 10,000 cycles with negligible capacity decay. This organic molecule preintercalation design provides a viable strategy for the development of stable cathode materials for CIBs.
Chen et al. (Tue,) studied this question.