Antimony doping improves the performance of cobalt‑vanadium hydrotalcite as the electrode of supercapacitors

Abstract

Due to its limited charge transfer capability, the layered double hydroxides (LDHs) material struggles to fully realize its ultra-high theoretical energy storage capacity when utilized as a supercapacitor electrode. The introduction of heteroatoms is widely regarded as an effective strategy for modulating charge distribution in LDHs materials. Herein, to address the issue of weak conductivity, the local charge distribution of CoV LDHs nanomaterials was modified through elemental doping with the metal element antimony, thereby enhancing their intrinsic charge conduction capabilities. As a result, the Sb-CoV LDHs-0.2 exhibits a specific capacitance of 326.7 F g⁻¹ at a current density of 1 A g⁻¹, which is 1.6 times higher than that of CoV-LDHs. Furthermore, the asymmetric supercapacitor, assembled with Sb-CoV LDHs-0.2 as the positive electrode and commercial activated carbon (AC) as the negative electrode, achieves an energy density of 10.1 Wh kg⁻¹ at a power density of 943.6 W kg⁻¹. Additionally, under a current density of 5 A g⁻¹, the device demonstrates remarkable cycling stability, with no observable capacity attenuation after 10,000 consecutive charge-discharge cycles. These results suggest that antimony elements significantly enhance the charge transfer and durability of LDHs materials.