锑(Sb)由于其高理论容量(660mAhg-1)和低氧化还原电压(0.2-0.9VvsNa/Na)而被认为是钠离子电池(SIB)的有前途的阳极。然而,电池放电/充电过程中体积变化引起的容量下降阻碍了实际应用。在这里,在DFT计算的指导下,通过对Fe和Sb2S3混合粉末进行退火制备Sb/Fe2S3。接下来,通过球磨将Sb/Fe2S3与15重量%的石墨混合,产生固定在膨胀石墨复合材料上的纳米Sb/Fe2S3(表示为Sb/Fe2S3-15%)。当用作SIB的阳极时,Sb/Fe2S3-15%在1、2、4、6、8和10Ag-1的电流速率下分别提供565、542、467、366、285和236mAhg-1的可逆容量,超过大多数基于Sb的阳极。高度导电的Fe2S3和Sb的共存使阳极的极化最小化。我们的实验证明,Sb和Fe2S3相在放电/充电循环过程中是可逆的,片状石墨可以加速Na+的扩散和电子传导。本文提出的合成方法也适用于合成各种锑/过渡金属硫化物异质结构(Sb/M1-xS),可以应用于一系列领域。
Antimony (
Sb) has been considered a promising anode for sodium-ion batteries (SIBs) owing to its high theoretical capacity (660 mA h g-1) and low redox voltage (0.2-0.9 V vs Na+/Na). However, the capacity degradation caused by the volumetric variation during battery discharge/charge hinders the practical application. Herein, guided by the DFT calculation,
Sb/Fe2S3 was fabricated by annealing Fe and Sb2S3 mixed powder. Next,
Sb/Fe2S3 was blended with 15 wt % graphite by ball milling, yielding nano-
Sb/Fe2S3 anchored on an exfoliated graphite composite (denoted as
Sb/Fe2S3-15%). When applied as an anode of SIBs, Sb/Fe2S3-15% delivered reversible capacities of 565, 542, 467, 366, 285, and 236 mA h g-1 at current rates of 1, 2, 4, 6, 8, and 10 A g-1, respectively, surpassing most of the Sb-based anodes. The co-existence of highly conductive Fe2S3 and
Sb minimizes the polarization of the anode. Our experiments proved that the Sb and Fe2S3 phases were reversible during discharge/charge cycling, and the exfoliated graphite can accelerate the Na+ diffusion and e- conduction. The proposed synthesis method of this work can also be applicable to synthesize various antimony/transition metal sulfide heterostructures (Sb/M1-xS), which may be applied in a series of fields.