Abstract:
The design and synthesis of novel heterostructured electrode materials are crucial to enable the fabrication of efficient supercapacitor devices. In this regard, transition metal phosphochalcogenides (S, Se) are promising candidates owing to their exotic electronic properties. Herein, a facile two-step hydrothermal protocol was used to synthesize binary and ternary metal phospho-selenide electrodes (Mn-Fe-P-Se, V-Fe-P-Se, Mn-V-P-Se, and Mn-Fe-V-P-Se). The chemical composition, morphology, and structure of the as-fabricated materials were fully investigated. The three-electrode electrochemical evaluation at 1.0 A g-1 demonstrated that the ternary metal electrode (MFVP-Se) exhibits a high capacity of 1968.63 C g-1. To assess the practical value of the rationally designed Mn-Fe-V-P-Se electrode material, Mn-Fe-V-P-Se was used as a positive electrode coupled with activated carbon (AC) as a negative electrode to assemble a hybrid supercapacitor device. This Mn-Fe-V-P-Se//AC device delivers a power density of 1999.96 W kg-1 with a high energy density of 149.88 Wh kg-1 coupled with no capacity loss after 5000 charging/discharging cycles. Additionally, density functional theory calculations revealed that our electrode exhibits suitable adsorption energy for OH- ions with a minimal diffusion barrier for ions.
摘要:
新型异质结构电极材料的设计和合成对于制造高效的超级电容器器件至关重要。在这方面,过渡金属磷硫族化物(S,Se)由于其奇特的电子特性而成为有希望的候选人。在这里,使用简单的两步水热协议来合成二元和三元金属磷硒化物电极(Mn-Fe-P-Se,V-Fe-P-Se,Mn-V-P-Se,和Mn-Fe-V-P-Se)。化学成分,形态学,和结构的制造材料进行了充分的研究。在1.0Ag-1下的三电极电化学评估表明,三元金属电极(MFVP-Se)表现出1968.63Cg-1的高容量。为了评估合理设计的Mn-Fe-V-P-Se电极材料的实用价值,将Mn-Fe-V-P-Se用作正极,并将活性炭(AC)用作负极,以组装混合超级电容器装置。该Mn-Fe-V-P-Se//AC装置提供1999.96Wkg-1的功率密度,具有149.88Whkg-1的高能量密度,并且在5000个充电/放电循环后没有容量损失。此外,密度泛函理论计算表明,我们的电极对OH-离子表现出合适的吸附能,而对离子的扩散势垒最小。