Yaoyu Ren,Hui Deng,Rujun Chen,Yang Shen,Yuanhua Lin,Ce-Wen Nan
Cubic garnet-type Al-contained Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (Al-LLZTO) ceramics were prepared by conventional solid-state reaction using either Li 2 CO 3 or LiOH·H 2 O as Li source. The effects of Li source on the lithium ionic conductivity of Al-LLZTO ceramics were systematically investigated by comparing the synthesis processes and characteristics of the mother powders and the microstructures of the sintered pellets made with different Li sources. Different calcination processes of the raw materials mixtures with different Li sources are revealed by thermogravimetry-differential scanning calorimetry investigation. The mother powder derived from LiOH·H 2 O is of higher sintering activity than those made from Li 2 CO 3 at the same calcination temperature. For the LiOH·H 2 O-derived pellets, higher relative density and enhanced lithium-ion conductivity is achieved at a much lower sintering temperature of 1100 °C as compared with Li 2 CO 3 -derived pellets. The highest conductivity obtained at room temperature is 9.28 × 10 −4 S cm −1 , which is the highest value reported to date for the same Ta doping level.
Yixiao Zhang,Xue Ye,Han Fu,Yu Zhong,Xiuli Wang,Changdong Gu,Jiangping Tu
Ether-based polymer electrolyte shows promising potential for application in solid-state lithium batteries owing to its cost-effectiveness, excellent flexibility, and above all, remarkable stability to lithium metal anode. However, it still suffers from challenges related to low ionic conductivity and inferior oxidation resistance. Herein, an ether-based gel composite electrolyte containing Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 (LLZTO) ceramics (LL-GCE) is fabricated via an in-situ polymerization method which can guarantee good interface contact with electrodes. The ceramics not only activate the interaction between polymers and lithium salts, resulting in significantly enhanced ionic conductivity (7.9 × 10 −4 S cm −1 ), but also collaborate with poly(1,3-dioxolane) (PDOL) to construct favorable anion-rich solvation configurations, which effectively restrict the anion migration with Li + transference number significantly increased to 0.83. Furthermore, the regulated solvation structures can passivate the electrode surface with a high content of robust LiF components formed on the electrolyte/electrode interphase. Consequently, the composite electrolyte demonstrates excellent abilities to inhibit Li dendrite growth and match with high-voltage cathodes. For instance, the LiFePO 4 ||Li cell using such electrolyte conveys a capacity of 135.4 mAh/g and the capacity retention is 99.3 % after 250 cycles at 1C. The LiCoO 2 ||Li full cell also shows excellent cycling performance. This work provides an effective strategy to modify ether-based polymer electrolytes and can boost their development in high-performance solid state lithium metal batteries.