Skov Lasse N, Grinderslev Jakob B, Kjær Therese S S, Kristensen Lasse R, Jensen Torben R
Interdisciplinary Nanoscience Center (iNANO) and, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark.
Angew Chem Int Ed Engl. 2025 Apr 7;64(15):e202500613. doi: 10.1002/anie.202500613. Epub 2025 Feb 5.
Solid-state batteries created from abundant elements, such as calcium, may pave the way for cheaper and safer electrical energy storage. Here we report a new type of solid calcium hydridoborate electrolyte, Ca(BH) ⋅ 2NHCH, with a high ionic conductivity of σ(Ca) ~10 S cm at T=70 °C, which is assigned to a relatively open and flexible structure with apolar moieties and weak dihydrogen bonds that facilitate migration of Ca ions in the solid state. The compound display a low electronic conductivity, providing an ionic transport number close to unity (t=0.9916). Calcium plating is observed for a Ca|Ca(BH) ⋅ 2NHCH|Pt electrochemical cell and the electrodes are investigated using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS) that reveal a rugged Ca anode surface owing to the stripping process and the presence of Ca-containing domains on the Pt working electrode from the plating process. Improved electrochemical reversiblity was achieved in a three-electrode cell configuration using a CaSn counter and reference electrode and a Sn working electrode, CaSn | Ca(BH) ⋅ 2NHCH | Sn, providing reversible Ca plating and stripping.
由钙等丰富元素制成的固态电池可能为更廉价、更安全的电能存储铺平道路。在此，我们报告一种新型的固态氢硼化钙电解质Ca(BH)₄·2NH₃CH₃，在T = 70°C时具有高离子电导率σ(Ca) ~10⁻⁵ S cm⁻¹，这归因于其具有相对开放且灵活的结构，带有非极性部分和弱二氢键，有助于Ca离子在固态中的迁移。该化合物显示出低电子电导率，提供接近1的离子迁移数（t = 0.9916）。在Ca|Ca(BH)₄·2NH₃CH₃|Pt电化学电池中观察到钙电镀现象，并使用扫描电子显微镜（SEM）结合能量色散X射线光谱（EDS）对电极进行研究，结果表明由于剥离过程，Ca阳极表面粗糙，且在Pt工作电极上存在来自电镀过程的含钙区域。在使用CaSn对电极和参比电极以及Sn工作电极的三电极电池配置CaSn|Ca(BH)₄·2NH₃CH₃|Sn中实现了改善的电化学可逆性，提供可逆的钙电镀和剥离。
