Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering , Chinese Academy of Sciences , Beijing 100190 , P. R. China.
University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.
ACS Appl Mater Interfaces. 2018 Jun 20;10(24):20412-20421. doi: 10.1021/acsami.8b03391. Epub 2018 Jun 12.
Rechargeable lithium (Li) metal batteries are considered the most promising of Li-based energy storage technologies. However, tree-like dendrite produced by irregular Li electrodeposition restricts it wide applications. Herein, based on a cation-microphase-regulation strategy, we create solid-liquid electrolytes (SLEs) by absorbing commercial liquid electrolytes into polyethylene glycol (PEG) engineered nanoporous AlO ceramic membranes. By means of molecular dynamics simulations and comprehensive experiments, we show that Li ions are regulated and promoted in the two microphases, the channel phase and nonchannel phase, respectively. The channel phase can achieve homogeneous Li flux distribution by multiple mechanisms, including its uniform array of nanochannels and ability to suppress lateral dendrite growth by its high modulus. In the nonchannel phase, PEG chains swollen by electrolyte facilitate desolvation and fast conduction of Li. As a result, the studied SLEs exhibit high ionic conductivity, low interfacial resistance, and the unique ability to stabilize deposition at the Li anode. By means of galvanostatic cycling studies in symmetric Li cells and Li/LiTiO cells, we further show that the materials open a path to Li metal batteries with excellent cycling performance.
可充电的锂 (Li) 金属电池被认为是最有前途的基于 Li 的储能技术之一。然而，由于不规则的 Li 电沉积产生的树状枝晶，限制了其广泛应用。在此，我们基于阳离子微相调控策略，通过将商业液态电解质吸收到聚乙二醇 (PEG) 工程化纳米多孔 AlO 陶瓷膜中，制备了固-液电解质 (SLE)。通过分子动力学模拟和综合实验，我们表明 Li 离子分别在通道相和非通道相这两个微相中被调控和促进。通道相通过多种机制可以实现均匀的 Li 通量分布，包括其纳米通道的均匀排列以及通过其高模量抑制侧向枝晶生长的能力。在非通道相中，电解质溶胀的 PEG 链有利于去溶剂化和 Li 的快速传导。结果，所研究的 SLE 表现出高离子电导率、低界面电阻以及稳定 Li 阳极沉积的独特能力。通过在对称 Li 电池和 Li/LiTiO 电池中的恒电流循环研究，我们进一步表明，这些材料为具有优异循环性能的 Li 金属电池开辟了道路。
