Non-equilibrium microstructure of Li1.4Al0.4Ti1.6(PO4)(3) superionic conductor by spark plasma sintering for enhanced ionic conductivity
Non-equilibrium microstructure of Li1.4Al0.4Ti1.6(PO4)(3) superionic conductor by spark plasma sintering for enhanced ionic conductivity
复制标题
放电等离子体烧结Li1.4Al0.4Ti1.6(PO4)(3)超离子导体的非平衡微观结构增强离子电导率
DOI：
10.1016/j.nanoen.2018.06.050
复制
发表时间：
2018
期刊：
影响因子：
17.6
通讯作者：
Yang Bing
中科院分区：
文献类型：
--
作者：
Duan Shanshan;Jin Hongyun;Liu Jiale;Ren Yazhou;Chen Ying;Lu Luhua;Tian Xiaocong;Hou Shuen;Yu Junxi;Li Jiangyu;Esfahani Ehsan Nasr;Yang Bing
在固态电解质中，晶界处的大电阻仍然是高离子电导率的瓶颈。在这里，我们开发了一种替代的和有点违反直觉的策略，通过非平衡微观结构来提高其离子电导率。以Li1.4Al0.4Ti1.6（PO4）3为例，我们证明了放电等离子烧结可以在结晶良好的陶瓷相和非晶玻璃相之间诱导出半结晶的中间相，在没有任何掺杂的情况下，得到的总离子电导率为1.3 × 10−3S cm− 1，比传统方法得到的电导率高2个数量级。进一步证明了非平衡结构在室温下是稳定的，但通过退火可以转变为具有更高结晶度但更低离子电导率的平衡结构，证明了非平衡结构确实是高性能的关键。这为其在电动汽车中的应用打开了大门，该策略也适用于其他离子系统。
In solid-state electrolytes, the large resistance at grain boundaries remains the bottleneck for high ionic conductivity. Here we develop an alternative and somewhat counterintuitive strategy to enhance their ionic conductivity via non-equilibrium microstructure. Using Li1.4Al0.4Ti1.6(PO4)3as an example, we demonstrate that semi-crystalline interphase between well crystallized ceramic phase and amorphous glass phase can be induced by spark plasma sintering, resulting in total ionic conductivity of 1.3 × 10−3S cm−1without any doping, which is 2 orders of magnitude higher than that derived by the conventional method. It is further demonstrated that the non-equilibrium structure is stable in ambient condition, yet can be converted into equilibrium structure by annealing with higher crystallinity but much lower ionic conductivity, proving that the non-equilibrium structure is indeed the key to the high performance. This opens door for its applications in electric vehicles, and the strategy is applicable to other ionic systems as well.