LiSi-CoS2体系热电池的电化学特性

为了了解人工合成的多孔CoS2材料的电压、负载能力、内阻、比功率、比容量等电化学特性,以小组合LiSi-CoS2体系热电池的形式,在真实的热电池工作温度环境下放电,结合电子扫描分析(SEM)、比表面分析(BET)等手段进行了试验分析,同时与LiSi-FeS2体系作了比较;并根据-180目、-260目、-400目三种粒度CoS2材料的电化学特性对比结果分析了粒度对该材料电化学性能的影响。试验表明本试验采用的多孔结构CoS2材料总体电化学性能优于FeS2。内阻较低,负载能力强,大电流极化较小,变负载下输出电压精度高,因此该多孔结构CoS2材料很适合于高比功率热电池产品;比容量较大,活性物质利用率较高,适合高比能量、长寿命热电池;粒度对材料的电化学性能有一定程度的影响,-180目、-260目、-400目三种粒度相比,颗粒度小的CoS2电压坪阶、脉冲电压、比功率均较高,内阻较低,比容量略有差别,但对于本试验可以忽略。

Electrochemical characteristics of the LiSi-CoS2 thermal batteries

To learn the electrochemical characteristics of the porous synthesized cobalt disulfide powder such as voltage output, ampere load capacity, internal impedance, power density, specific capacity and etc. under the actual thermal battery's interior temperature environment, small LiSi-CoS2 thermal batteries were tested and compared with LiSi-FeS2 thermal batteries. By virtue of the analysis results of XRD, TGA, SEM and BET, the electrochemical characteristics of the CoS2 powder were discussed. To learn about the relation of granularity of powder with its performances, -180 mesh, -260 mesh and -400 mesh CoS2 powder were tested. It shows that the CoS2 powder is superior to the FeS2 powder in respect to its lower internal impedance, stronger loading capacity, smaller polarization under larger current, higher voltage precision with current variety, higher specific capacity and active material utilization. So the CoS2 powder may be more suitable for high power, high energy density and long-life thermal batteries application. According to the performances of -180 mesh, -260 mesh and -400 mesh CoS2 powder, the battery with smaller granularity CoS2 cathode has higher voltage plateau, pulse voltage, power density, lower internal impedance and comparative capacity.