论文标题
伪TI-V氢化物的机械化学合成及其与Li和Na的转化反应
Mechanochemical synthesis of pseudobinary Ti-V hydrides and their conversion reaction with Li and Na
论文作者
论文摘要
基于插入电极的锂离子电池（LIB）达到了内在容量限制。性能提高和成本降低需要替代性反应机制和新型的电池化学，例如转换反应和钠离子电池（NABS）。我们在这里研究Ti1-XVXH2氢化物（0 <x <1）的形成及其作为LIBS和NABS半细胞中的阳极的电化学特性。氢化物是通过氢气气氛（pH2〜8 MPa）下的金属粉末的机械化学合成的。对于低于80 at。％（x <0.8）的V含量，形成了单相假二氢化合物TI1-XVXH2。它们在荧光岩型结构中结晶，并具有高度纳米结构（结晶石尺寸<10 nm）。它们的晶格参数随V含量导致氢化物不稳定的V含量降低。电化学研究首先是在锂离子半细胞中进行的，在Ti1-XVXH2氢化物和锂之间进行了完全转化。转化反应的潜力可以通过钒含量逐渐调节，这是由于其不稳定的效果。此外，对于富含Ti的（X <0.25）和富含V（X> 0.7）合金，可以观察到转化反应的不同路径。 NA-ION半细胞测量结果证明了（V，Ti）H2 Hydrides和钠之间的反应性，尽管具有显着的动力学局限性
Lithium-ion batteries (LiBs) based on insertion electrodes reach intrinsic capacity limits. Performance improvements and cost reduction require alternative reaction mechanisms and novel battery chemistries such as conversion reactions and sodium-ion batteries (NaBs), respectively. We here study the formation of Ti1-xVxH2 hydrides (0 < x < 1) and their electrochemical properties as anodes in LiBs and NaBs half-cells. Hydrides were synthesized by mechanochemistry of the metal powders under hydrogen atmosphere (PH2~ 8 MPa). For V contents below 80 at.% (x < 0.8), single-phase pseudobinary dihydride compounds Ti1-xVxH2 are formed. They crystallize in the fluorite-type structure and are highly nanostructured (crystallite size < 10 nm). Their lattice parameter decreases linearly with the V content leading to hydride destabilization. Electrochemical studies were first carried out in Li-ion half cells with full conversion between Ti1-xVxH2 hydrides and lithium. The potential of the conversion reaction can be gradually tuned with the vanadium content due to its destabilization effect. Furthermore, different paths for the conversion reaction are observed for Ti-rich (x < 0.25) and V-rich (x > 0.7) alloys. Na-ion half-cell measurements prove the reactivity between (V,Ti)H2 hydrides and sodium, albeit with significant kinetic limitations
