Zirconium trisulfide as a promising cathode material for Li primary thermal batteries

In this work ZrS3 has been synthesized by solid state reaction in a sealed quartz tube and investigated as a candidate cathode material in Li thermal batteries. The structure of ZrS3 before and after cell testing has been studied using powder X-ray diffraction. A new spinel related material, LiZr2S4, has been identified as the product of the electrochemical process, which can be indexed to a = 10.452(8) Å cubic unit cell. The electrochemical properties of the batteries were investigated at 500 °C against Li13Si4 by galvanostatic discharge and galvanostatic intermittent titration technique (GITT). In a thermal Li cell at 500 °C a single voltage plateau of 1.70 V at a current density of 11 mA/cm2 was achieved with capacity of 357 mA h g-1. Therefore ZrS3 material has some promise as a cathode for Li thermal batteries.Publisher PDFPeer reviewe

Transition metal chlorides NiCl2, KNiCl3, Li6VCl8 and Li2MnCl4 as alternative cathode materials in primary Li thermal batteries

Special thanks to AWE Plc for their support and funding for this work. The authors would also like to acknowledge the EPSRC Platform Grant EP/K015540/1 and the Royal Society Wolfson Merit Award WRMA 2012/R2.Transition metal chlorides KNiCl3, Li6VCl8 and Li2MnCl4 were synthesized by solid state reaction in sealed quartz tubes and investigated as candidate cathode materials along with NiCl2 in Li thermal batteries. The structure and morphology were studied and electrochemical properties probed at high temperatures (400°C–500°C) against Li13Si4 by galvanostatic discharge and galvanostatic intermittent titration technique (GITT). All the transition metal chlorides reduced to metal and the products of the discharge mechanism were confirmed by powder X-ray diffraction. NiCl2 was tested at 500°C and a capacity of 360 mAhg−1 was achieved. KNiCl3 was tested at different current densities from 15 mA/cm2 to 75 mA/cm2 and a high voltage profile 2.30V was achieved at 425°C with a capacity of 262 mAhg−1. Li6VCl8 was tested at 500°C and a 1.80V voltage plateau at a current density of 7.5 mA/cm2 was achieved with a capacity of 145 mAhg−1. Li2MnCl4 was tested at the same current density at 400°C and a capacity of 254 mAhg−1 was achieved. These transition metal chlorides exhibit higher voltage against Li13Si4 and, hence, provide more specific power compared to the well-known metal disulfides MS2 (M = Fe, Co, Ni) and may be promising cathode materials for Li thermal batteries.Publisher PDFPeer reviewe

In-situ studies of high temperature thermal batteries : a perspective

Funding: UK Engineering and Physical Sciences Research Council (EP/P007821/1).Here we present a perspective on in-situ studies of high temperature batteries. We focus on a primary battery technology- the thermal battery- which possesses a molten salt electrolyte. We discuss aspects of sample environment design, data collection and will briefly look at some case studies. We aim to highlight the importance of using in-situ techniques in studying electrochemical devices such as high temperature batteries.Publisher PDFPeer reviewe

Development of the Ca/FeS₂ chemistry for thermal batteries

Alternative battery chemistries are the focus of growing attention due to their potential advantages over lithium; however, the field of thermal batteries sees much less research into alternative chemistries, as the current lithium alloy–metal sulfide cell is seen as the “gold standard”. In this work, we demonstrate the operation of a thermal battery using a calcium-containing eutectic and calcium metal against the FeS2 cathode material. An initial assessment of the CaCl2–NaCl eutectic is presented, showing that it is a good candidate for use as an electrolyte. Cells were assembled and characterized using a range of physical and electrochemical techniques, and their properties were studied. Discharge voltages at low current densities were promising, with cells displaying discharge voltages >2 V and capacities in excess of 100 mAh g–1. Rate capability was also explored, which can be improved by modification of the cathode. Although the cathode material was not fully utilized during discharge, there was evidence of electrochemical reactions occurring, which were explored in detail using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and neutron diffraction. It is hoped that these results will stimulate development and ideas for high-temperature battery chemistries, expanding the horizons of these types of batteries for new applications