Dataset of "Photoactivity Enhancement by Electrochemical Activation of Bifunctional V2C@S MXene: Desirable Approach in Single-architecture High-rate Zinc-ion Solar Batteries"

Single-architecture solar battery energy storage devices which are capable of storing energy from solar energy harvesting in only one package, are being developed as the upcoming and future off-grid energy storage systems. In this research, we explore the photo-responsive characteristics and application of vanadium-based MXene in pouch zinc-ion solar batteries. In addition to the pristine V2CTx MXene, a sulfur-incorporated nanocomposite of V2CTx@S was synthesized via a reaction between exfoliated V2CTx MXene and sulfur at a high benign temperature to evaluate the efficiency of both as photocathodes for such state-of-the-art devices. Through the initial electrochemical charging activation, photoactivity of the V2CTx@S photocathode was enhanced significantly because of the formation of nanoscale vanadium oxide on the surface of conductive V2CTx MXene and the presence of sulfur element without losing the MXene nanolayered characteristics. The results of the pouch zinc-ion solar battery made by V2CTx@S indicate a specific capacity of 197 mAh g–1 at 1 A g–1 under illumination, compared to the dark condition with the amount of 114 mAh g–1 at 1 A g–1 (72.8% enhancement). Additionally, the V2CTx@S zinc-ion solar battery carried out a photo-charging voltage response of 700 mV, and a remarkable energy density of 255 Wh kg–1 at 1 A g–1 under illumination compared to dark conditions with the energy density of 150 Wh kg–1 at 1 A g‒1. Furthermore, a photoconversion efficiency of ≈2.04% was obtained in the pouch zinc-ion solar battery. Density functional theory studies supported these experimental findings by revealing that sulfur modification and vanadium oxide formation improve the electronic properties and light absorption capabilities of the pristine V2C MXene, contributing to its superior photocathodic performance. These great achievements in photo-electrochemical behaviors of V2CTx@S are due to the catalytic synergy of bifunctional MXene decorated with sulfur element, the formation of outer high-valence vanadium oxide, and inner conductive of V2CTx. The findings provide crucial insights into designing of highly efficient photocathode materials for advanced solar batteries.仅通过单一封装即可存储太阳能采集能量的单架构太阳能储能电池，正作为下一代及未来离网储能系统被研发。本研究针对软包锌离子太阳能电池，探究了钒基MXene（vanadium-based MXene）的光响应特性与应用场景。除原始V2CTx MXene外，本研究通过剥离态V2CTx MXene与硫在温和高温下的反应，合成了掺硫型V2CTx@S纳米复合材料，以评估二者作为此类前沿器件光阴极的效率。通过初始电化学充电活化，V2CTx@S光阴极的光活性得到显著提升，这归因于导电V2CTx MXene表面形成了纳米级氧化钒，且硫元素的引入并未破坏MXene的纳米层状结构特性。以V2CTx@S制备的软包锌离子太阳能电池测试结果显示：在光照条件下1 A g–1电流密度时，其比容量可达197 mAh g–1；而在暗态条件下，同电流密度下比容量仅为114 mAh g–1，性能提升幅度达72.8%。此外，该V2CTx@S锌离子太阳能电池在光照条件下1 A g–1电流密度时，展现出700 mV的光充电电压响应，以及高达255 Wh kg–1的能量密度；而暗态条件下同电流密度时能量密度仅为150 Wh kg–1。此外，该软包锌离子太阳能电池的光电转换效率约为2.04%。密度泛函理论（Density Functional Theory, DFT）研究验证了上述实验结果：硫掺杂与氧化钒的形成可优化原始V2C MXene的电子性能与光吸收能力，进而提升其优异的光阴极性能。V2CTx@S优异的光电化学性能，源于硫修饰双功能MXene的催化协同作用、表面高价钒氧化物的形成，以及内部V2CTx的高导电特性。本研究结果为先进太阳能电池高效光阴极材料的设计提供了关键参考。