Fu Kun Kelvin, Gong Yunhui, Dai Jiaqi, Gong Amy, Han Xiaogang, Yao Yonggang, Wang Chengwei, Wang Yibo, Chen Yanan, Yan Chaoyi, Li Yiju, Wachsman Eric D, Hu Liangbing
University of Maryland Energy Research Center, University of Maryland, College Park, MD 20742; Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742.
University of Maryland Energy Research Center, University of Maryland, College Park, MD 20742;
Proc Natl Acad Sci U S A. 2016 Jun 28;113(26):7094-9. doi: 10.1073/pnas.1600422113. Epub 2016 Jun 15.
Beyond state-of-the-art lithium-ion battery (LIB) technology with metallic lithium anodes to replace conventional ion intercalation anode materials is highly desirable because of lithium's highest specific capacity (3,860 mA/g) and lowest negative electrochemical potential (∼3.040 V vs. the standard hydrogen electrode). In this work, we report for the first time, to our knowledge, a 3D lithium-ion-conducting ceramic network based on garnet-type Li6.4La3Zr2Al0.2O12 (LLZO) lithium-ion conductor to provide continuous Li(+) transfer channels in a polyethylene oxide (PEO)-based composite. This composite structure further provides structural reinforcement to enhance the mechanical properties of the polymer matrix. The flexible solid-state electrolyte composite membrane exhibited an ionic conductivity of 2.5 × 10(-4) S/cm at room temperature. The membrane can effectively block dendrites in a symmetric Li | electrolyte | Li cell during repeated lithium stripping/plating at room temperature, with a current density of 0.2 mA/cm(2) for around 500 h and a current density of 0.5 mA/cm(2) for over 300 h. These results provide an all solid ion-conducting membrane that can be applied to flexible LIBs and other electrochemical energy storage systems, such as lithium-sulfur batteries.
超越现有技术水平，采用金属锂阳极的锂离子电池（LIB）技术来取代传统的离子嵌入阳极材料是非常可取的，因为锂具有最高的比容量（3860 mA/g）和最低的负电化学势（相对于标准氢电极约为3.040 V）。在这项工作中，据我们所知，我们首次报道了一种基于石榴石型Li6.4La3Zr2Al0.2O12（LLZO）锂离子导体的三维锂离子传导陶瓷网络，以在基于聚环氧乙烷（PEO）的复合材料中提供连续的Li(+)传输通道。这种复合结构进一步提供结构增强，以提高聚合物基体的机械性能。柔性固态电解质复合膜在室温下表现出2.5×10(-4) S/cm的离子电导率。该膜在室温下重复锂剥离/电镀过程中，能有效阻止对称Li |电解质| Li电池中的枝晶生长，在0.2 mA/cm(2)的电流密度下可持续约500 h，在0.5 mA/cm(2)的电流密度下可持续超过300 h。这些结果提供了一种全固态离子传导膜，可应用于柔性锂离子电池和其他电化学储能系统，如锂硫电池。
