Uniformly confined V2O3 quantum dots embedded in biomass derived mesoporous carbon toward fast and stable energy storage

Rational composition and structural design of electrode substances are critical for lithium-ion batteries (LIBs) supercapacitors (SCs) with good cycling steadiness and superb rate capability. Therefore, we report a electrode material consisting of V2O3 quantum dots (QDs, about 6.64 nm) well-distributed on mesoporous carbon (MC) nanosheets. V2O3 has high intrinsic conductivity and an open tunnel-like lattice structure, facilitating electron transfer and ion intercalation. The composite architectures can offer more electrochemical active shorten ion/electron diffusion paths, and reduce volume swings during the charging/discharging process. synergic effect of these merits significantly improves the reaction kinetics and prevents structural damage to entire electrode. As a result, V2O3-QDs/MC nanosheets exhibit a large capacity/capacitance, excellent cycling steadiness, and high rate performance. For LIBs, V2O3-QDs/MC displays a great reversible capacity of 931 g- 1 at 0.2 A g-1 over 500 cycles and fast and stable lithium storage behaviors with 822 mAh g-1 at 2 A g-1 1000 cycles. For SCs, V2O3-QDs/MC manifests a considerable specific capacitance of 270 F g-1 at 1 A g-1 satisfactory durability for at least 5000 cycles at 10 A g-1. This work informs a good structure design for structing advanced metal oxide-based nanostructured electrode materials.

Automated summary

This study reports an electrode material consisting of V2O3 quantum dots (QDs) well-distributed on mesoporous carbon (MC) nanosheets for lithium-ion batteries (LIBs) and supercapacitors (SCs) with good cycling stability and excellent rate performance. The V2O3-QDs/MC composite architecture offers more electrochemical active sites, shortens ion/electron diffusion paths, and reduces volume swings during the charging/discharging process. As a result, it exhibits a large capacity/capacitance, excellent cycling stability, and high rate performance for LIBs and SCs.