Transition metal selenides have received great attention as promising anode materials for sodium-ion batteries (SIBs). However, it still faces the change of volume and structure, which reduces the rate performance and cycle stability in cycle process. The design of micro-nano hierarchical structure is an important method to improve the structural stability and reaction kinetics in discharge-charge process. In this study, the micro-nano Cu₂Se is synthesized using a simple solvothermal and annealing treatment method, and it shows excellent electrochemical performance as anode material for SIBs. It exhibits excellent rate capacity (373.8 mAh g⁻¹ at 0.1 A g⁻¹ and 303.48 mAh g⁻¹ when the current density is increased to 10 A g⁻¹) and cycling stability (250.3 mAh g⁻¹ after 4000 cycles at 5 A g⁻¹, achieving 85.80% for retention rate). In addition, the deep reaction mechanism of Cu₂Se has been explored through ex situ XRD and HRTEM.

过渡金属硒化物作为钠离子电池（SIB）的有前途的负极材料受到了极大的关注。但仍面临体积和结构的变化，降低了循环过程中的倍率性能和循环稳定性。微纳分级结构的设计是提高充放电过程中结构稳定性和反应动力学的重要方法。本研究采用简单的溶剂热和退火处理方法合成了微纳米Cu _{2 Se，它作为SIBs的负极材料表现出优异的电化学性能。}它表现出优异的倍率容量（0.1 A g ^-1时为373.8 mAh g ^-1，当电流密度增加到 10 A g -1 时为 303.48 mAh g ^-1-1）和循环稳定性（在 5 A g ^-1下 4000 次循环后为250.3 mAh g ^-1，保留率达到 85.80%）。此外，通过非原位XRD和HRTEM探索了Cu ₂ Se的深层反应机理。