Hybrid electrolytes with 3D bicontinuous ordered ceramic and polymer microchannels for all-solid-state batteries
Hybrid electrolytes with 3D bicontinuous ordered ceramic and polymer microchannels for all-solid-state batteries
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DOI：
10.1039/c7ee02723k
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发表时间：
2018-01
影响因子：
32.5
通讯作者：
Stefanie Zekoll;Cassian Marriner-Edwards;A. Hekselman;Jitti Kasemchainan;C. Kuss;D. Armstrong;D. Cai-D.-Ca
中科院分区：
文献类型：
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作者：
Stefanie Zekoll;Cassian Marriner-Edwards;A. Hekselman;Jitti Kasemchainan;C. Kuss;D. Armstrong;D. Cai-D.-Ca
报道了由三维有序双连续导电陶瓷和绝缘聚合物微通道组成的杂化固体电解质。陶瓷通道提供连续的、不间断的通道，在电极之间保持高离子电导率，而聚合物通道允许改善陶瓷本身的机械性能，特别是减轻陶瓷的脆性。陶瓷电解质的导电性通常受到晶界电阻的限制，因此需要致密的陶瓷。三维有序杂化材料的电导率仅受陶瓷占据的体积分数的影响，表明陶瓷通道可以烧结成高密度，类似于致密的陶瓷盘。混合电解质采用陶瓷锂离子导体Li1.4Al0.4Ge1.6(PO4)3 （LAGP）进行演示。通过负复制3D打印聚合物模板制备具有空通道的结构化LAGP 3D支架。用不导电的聚丙烯（PP）或环氧聚合物（环氧）填充空通道，形成具有三维双连续陶瓷和聚合物微通道的结构化混合电解质。印刷模板允许精确控制陶瓷与聚合物的比例和微结构；通过形成立方结构、回旋结构、菱形结构和旋轴结构证明了这一点。电学和机械性能取决于微结构，填充环氧树脂的陀螺仪提供了电导率和机械性能的最佳组合。在室温下，离子电导率为1.6 × 10−4 S cm−1，而烧结LAGP球团的电导率仅受陶瓷所占体积分数的影响。旋转LAGP -环氧电解质的力学性能表明，在破裂前，LAGP颗粒的压缩破坏应变高达28%，弯曲破坏应变高达5倍。值得注意的是，这表明有序陶瓷和聚合物混合电解质可以在不显著影响离子电导率的情况下具有优越的机械性能，这解决了全固态电池的关键挑战之一。
Hybrid solid electrolytes, composed of 3D ordered bicontinuous conducting ceramic and insulating polymer microchannels are reported. The ceramic channels provide continuous, uninterrupted pathways, maintaining high ionic conductivity between the electrodes, while the polymer channels permit improvement of the mechanical properties from that of the ceramic alone, in particular mitigation of the ceramic brittleness. The conductivity of a ceramic electrolyte is usually limited by resistance at the grain boundaries, necessitating dense ceramics. The conductivity of the 3D ordered hybrid is reduced by only the volume fraction occupied by the ceramic, demonstrating that the ceramic channels can be sintered to high density similar to a dense ceramic disk. The hybrid electrolytes are demonstrated using the ceramic lithium ion conductor Li1.4Al0.4Ge1.6(PO4)3 (LAGP). Structured LAGP 3D scaffolds with empty channels were prepared by negative replication of a 3D printed polymer template. Filling the empty channels with non-conducting polypropylene (PP) or epoxy polymer (epoxy) creates the structured hybrid electrolytes with 3D bicontinuous ceramic and polymer microchannels. Printed templating permits precise control of the ceramic to polymer ratio and the microarchitecture; as demonstrated by the formation of cubic, gyroidal, diamond and spinodal (bijel) structures. The electrical and mechanical properties depend on the microarchitecture, the gyroid filled with epoxy giving the best combination of conductivity and mechanical properties. An ionic conductivity of 1.6 × 10−4 S cm−1 at room temperature was obtained, reduced from the conductivity of a sintered LAGP pellet only by the volume fraction occupied by the ceramic. The mechanical properties of the gyroid LAGP–epoxy electrolyte demonstrate up to 28% higher compressive failure strain and up to five times the flexural failure strain of a LAGP pellet before rupture. Notably, this demonstrates that ordered ceramic and polymer hybrid electrolytes can have superior mechanical properties without significantly compromising ionic conductivity, which addresses one of the key challenges for all-solid-state batteries.