Nano-meter scaled evaluation for dynamic behavior of lithium ions in a micro secondary battery embedded in silicon substrate

在这个项目中，我们追求纳米尺度的评估锂离子在嵌入在硅衬底的微型二次电池的动态行为。为此，利用原子力显微镜（AFM）结合导电探针，对全固态锂二次电池（Al/Li/SiO_2-15at%P_2O_5/LiMn_2O_4/polycrystalline silicon）在5×5 μm^2面积内的表面形貌和充放电特性进行了同步观察。5×5 μm^2的电池面积表现出对应于2.9×10^<10>Li^+离子/μm^2移动的充放电行为，反映了Li^+离子的循环移动。Al电极由0.1 ~ 1.5 μm的鳞片状晶粒组成，在第一次充电过程中上升约30 nm。Al电极的表面显示出随着充电/放电操作从鳞状结构到褶皱结构的循环变化，表明阳极中过量的Li被拉入玻璃态电解质中。这些结果对未来的发展是有希望的。 ...更多信息 此外，我们还研究了锂离子在尖晶石LiMn_2 O_4正极中的动力学行为。为此，利用原子力显微镜（AFM）和导电探针对锂离子二次电池正极材料尖晶石LiMn_2O_4在3.5× 3.5 μm^2范围内的表面形貌进行了研究。在从LiMn_2O_4中引出Li^+离子的负偏压下，电流在5.5 V处突然增加，表明Li^+离子向表面传导。对应于电流的增加，覆盖整个表面的部分鳞片状晶粒扩展并变平，表明Li积累层中Mn-eg和O-2 p电子之间的排斥作用引起了Jahn-Teller相变。此外，还研究了新型固体电解质材料Li_3AlN_2和正极材料LiCoO_2的光电性能。为了制作100×100 μm^2尺寸的全固态电池，在Si衬底上制作了100 μm×100 μm× 2 μm尺寸的隔离孔。未来，我们将尝试将100×100 μm^2尺寸的电池嵌入微米级尺寸的孔中。少

In this project, we pursued nano-meter scaled evaluation for the dynamic behavior of lithium ions in a micro secondary battery embedded in silicon substrate. For this purpose, surface morphology and charge/discharge characteristic in a 5×5 μm^2 area of an all-solid-state Li secondary battery (Al/Li/SiO_2-15at%P_2O_5/LiMn_2O_4/polycrystalline silicon) embedded in a Si substrate are simultaneously observed by atomic force microscopy (AFM) with a conductive probe. The battery area of 5×5 μm^2 shows charge/discharge behavior corresponding to the movement of 〜2.9×10^<10> Li^+ ions/μm^2, reflecting the cyclic movement of Li^+ ions. The Al electrode consisting of scale-shaped grains of 0.1〜1.5 μm in size rises by 〜30 nm during the first charge operation. The surface of the Al electrode shows a cyclic change from scaly to wrinkled structures with the charge/discharge operations, indicating the drawing of the excess Li in the anode into the glassy electrolyte. These results are promising for th … More e realization of a micrometer-sized battery.Furthermore, we also studied the dynamic behavior of lithium ions in spinel-LiMn_2O_4 cathode. For this purpose, surface morphology in 3.5×x3.5 μm^2 area of spinel LiMn_2O_4, which is a typical cathode,material for Li ion secondary batteries, is studied using an atomic force microscopy (AFM) with a conductive probe. Under the negative bias voltage to extract Li^+ ions from LiMn_2O_4, electric current abruptly increases at 5.5 V, indicating Li^+ ionic conduction toward the surface. Corresponding to the increase in current, part of scale shaped grains covering the whole surface expand and flatten, suggesting the Jahn-Teller phase transition induced by the repulsive interaction between the Mn-eg and O-2p electrons in Li accumulated layer. Additionally, optical and electronic properties of a new solid state electrolyte material Li_3AlN_2 and a cathode material LiCoO_2 were studied. In order to fabricate 100×100 μm^2 sized all solid state batteries, isolated holes of 100 μm×100 μm× 2 μm in size were made in Si substrates. In the future, we will try the preparation for the 100×100 μm^2 sized batteries embedded in the mico-meter sized holes. Less