Bi_(2)Se_(3)/WSe_(2)异质结构花球的制备与储钠性能研究

Preparation of Bi_(2)Se_(3)/WSe_(2)Heterojunction Flower-like Spheres and Study on Sodium Storage Performance

钠离子电池(SIBs)由于在成本、资源和安全性方面具有显著优势,被认为是一种有前途的锂离子电池替代方案。然而,它的实际应用受到容量低、倍率性能差和寿命短等问题的限制。本文采用一步水热法合成了Bi_(2)Se_(3)/WSe_(2)花球异质结构,其中存在着丰富的孔隙。该结构可以在充放电过程中缓解体积效应,并且异质界面处的内建电场可以增强离子扩散反应,从而提高电化学性能。组装的Bi_(2)Se_(3)/WSe_(2)半电池具有较高的初始库仑效率、循环稳定性和较强倍率能力。经过100次循环,钠离子电池(SIBs)在0.1 A·g^(-1)下放电容量为402.6 mAh·g^(-1),在1 A·g^(-1)下进行500次循环后,总量可达298.3 mAh·g^(-1),而在高倍率下(5 A·g^(-1)),其容量仍能维持在259.1 mAh·g^(-1)。

Sodium-ion batteries(SIBs)are considered as a promising alternative to lithium-ion batteries due to their advantages in cost,resources,and safety.However,low capacity,poor rate capability,and short lifespan limits the practical application of SIBs.To address these issues,Bi_(2)Se_(3)/WSe_(2)flower-like heterostructures with abundant pore structure have been synthesized by a one-step hydrothermal method.This structure can mitigate the volume effect during charge and discharge process,and the built-in electric field at the heterojunction interface enhances ion diffusion reactions,thereby improving electrochemical performance.The assembled Bi_(2)Se_(3)/WSe_(2)half-cell exhibits high initial Coulombic efficiency,cycling stability,and rate capability.After 100 cycles,the discharge capacity at 0.1 A g^(-1)is 402.6 mAh·g^(-1),and after 500 cycles at 1 A·g^(-1),it reaches a specific capacity of 298.3 mAh·g^(-1).At high rates(5 A·g^(-1)),the capacity remains high at 259.1 mAh·g^(-1).