论文标题
谷物间相对通过火花等离子体烧结制备的LAGP固体电解质的离子电导率的影响
The Impact of Inter-grain Phases on the Ionic Conductivity of LAGP Solid Electrolyte Prepared by Spark Plasma Sintering
论文作者
论文摘要
LI1.5AL0.5GE1.5（PO4）3（LAGP）是全稳态电池的有前途的氧化物固体电解质，由于其出色的空气稳定性，广泛的电化学稳定性窗口和成本效益的前体材料。然而，由于存在谷物间相，其离子电导率性能进一步改善，从而阻碍了氧化物基于氧化物固态电解质的高级设计的主要障碍。这项研究建立并量化了谷物间相，其3D形态的影响，并形成了组成对在不同火花等离子体血浆烧结条件下制造的LAGP颗粒的整体离子电导率特性的影响。基于互补技术，例如PEIS，XRD，3D FIB-SEM断层扫描和固态MAS NMR，并与DFT建模相结合，对谷物间相微结构的深入了解，揭示了谷物间区域的区域间区域由LI4P2O7和无序的LI9AL3（P2O7）（P2O7）3（PO2O7）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3（PO4）3。我们证明，当无序的LI9AL3（P2O7）3（PO4）2相位占主导地位的谷物间区域组成，而从高度有序的LI4P2O7阶段降低贡献时，为680°C SPS制备实现了LAGP系统的最佳离子电导率。
Li1.5Al0.5Ge1.5(PO4)3 (LAGP) is a promising oxide solid electrolyte for all-solid-state batteries due to its excellent air stability, wide electrochemical stability window and cost-effective precursor materials. However, further improvement in their ionic conductivity performance is hindered by the presence of inter-grain phases leading to a major obstacle to the advanced design of oxide based solid-state electrolytes. This study establishes and quantifies the influence of inter-grain phases, their 3D morphology, and formed compositions on the overall ion conductivity properties of LAGP pellets fabricated under different Spark plasma sintering conditions. Based on complementary techniques, such as PEIS, XRD, 3D FIB-SEM tomography and solid-state MAS NMR coupled with DFT modelling, a deep insight into the inter-grain phase microstructures is obtained revealing that the inter-grain region is comprised of Li4P2O7 and a disordered Li9Al3(P2O7)3(PO4)2 phase. We demonstrate that optimal ionic conductivity for the LAGP system is achieved for the 680 °C SPS preparation when the disordered Li9Al3(P2O7)3(PO4)2 phase dominates the inter-grain region composition with reduced contributions from the highly ordered Li4P2O7 phases.
