Abstract: Intermetallic compound NiSb2 powder are prepared by levitation melting and ball-milling. The electrochemical lithium absorption / release properties of NiSb2 as a new lithium-ion batteries anode material were investigated. The experiments show the lithium absorption / release plateaus are at 0.8V and 1.0V respectively. It is found that the first reversible capacity of NiSb2 electrode reaches 494mAh·g-1 at a current density of 20mA·g-1, and the capacity of about 242mAh·g-1is still maintained even after 15 times cycling. But we also find that the reversible capacity decreases at the increased charge-discharge current density.
Lithium absorption and release mechanism of intermetallic compound NiSb2
Abstract：
Intermetallic compound NiSb 2 powder are prepared by levitation melting and ball-milling. The electrochemical lithium absorption / release properties of NiSb 2 as a new lithium-ion batteries anode material were investigated. The experiments show the lithium absorption / release plateaus are at 0.8 V and 1.0 V respectively. It is found that the first reversible capacity of NiSb 2 electrode reaches 494 mAh·g -1 at a current density of 20 mA·g -1 , and the capacity of about 242 mAh·g -1 is still maintained even after 15 times cycling. But we also find that the reversible capacity decreases at the increased charge-discharge current density.
图2 NiSb2电极在20 mA·g-1电流密度下的充放电曲线 (a) 和容量微分 (dQ / dV) 曲线 (b) Fig.2 Profiles of charge/discharge (a) and differential capacity (b) for NiSb2 electrode at current density of 20 mA·g-1
图3 不同充放电状态下NiSb2电极的XRD谱图 Fig.3 XRD patterns of NiSb2 electrodes at different discharge-charge states (a) —Initial battery; (b) —After first discharge to 0.8 V; (c) —After first discharge to 0.05 V; (d) —After first charge to 1.0 V; (e) —After first charge to 1.5 V
图4 NiSb2 电极的循环寿命曲线 Fig.4 Charge capacity vs cycle number of NiSb2 electrodes at different current density
