Jitao Yi,Xinyue Zhang,Shanliang Chen,Ting Sun,Qinghui Jiang,Yong Liu
BiCuSeO-based materials show great promise for thermoelectric generators in waste heat recovery due to their excellent thermoelectric properties. However, the limited focus on device development has hindered their industrial-scale implementation. Here, high-performance BiCuSeO-based compounds with exceptional thermal stability were synthesized and remained stable aging for 400 h, making them suitable for investigation in the device bonding process. The BiCu80AgP is identified as the optimal solder from eight candidates, effectively connecting the copper (Cu) electrode with BiCuSeO-based compounds. The optimized bonding process substantially resulted in an impressive interfacial shear strength of about 15 MPa and reduced interfacial resistance to 2.2 mΩ cm 2 . Interface analysis revealed the formation of diverse, complex compounds, with variations in their concentrations greatly affecting joint performance. Achieving a uniform distribution of these compounds effectively mitigated thermal expansion mismatches and extended joint longevity by a factor of 6.6. This research proposes a novel fabrication method for BiCuSeO-based thermoelectric devices utilizing BCu80AgP solder, providing a foundation for future advancements in this field.
Sulfide solid electrolytes have attracted wide attention due to their high ionic conductivity . Li 6 PS 5 Cl is one of the most promising electrolytes for all-solid-state lithium batteries with high-energy-density. It is reported that the disordered arrangement of Cl - in the aragonite structure has a significant effect on the conductivity of Li 6 PS 5 Cl. In this work, the disorder of anion sites is modestly regulated by adjusting the ratio of S and Cl in Li 6−x PS 5−x Cl 1+x electrolyte. In addition, to verify the commonality of this strategy, Li 5.6 PS 4.6 Cl 1.4 is prepared using self-made Li 2 S, and similar results are obtained. On this basis, the density of Li 5.6 PS 4.6 Cl 1.4 electrolyte sheet is improved by hot-pressing, which can successfully inhibit the growth of lithium dendrites . As expected, the ionic conductivity of the sulfide electrolyte and the electrochemical performance of the ASSLBs are greatly improved. A highest ionic conductivity of 8.2 × 10 −3 S cm −1 of Li 5.6 PS 4.6 Cl 1.4 is obtained at room temperature. A high capacity retention of 99.99 % is maintained for NCM811 @Li 2 O//Li 5.6 PS 4.6 Cl 1.4 //Li-In system after 400 cycles at 1 C with ultra-high cathode loading of 35.6 mg cm −2 . Besides, the cost of sulfide electrolytes can be reduced as the decreased usage of Li 2 S. This work proposes a novel synthesis method of low-cost and high-performance Li 6−x PS 5−x Cl 1+x electrolytes.