Liu Tao, Li Huajun, Yue Jinming, Feng Jingnan, Mao Minglei, Zhu Xiangzhen, Hu Yong-Sheng, Li Hong, Huang Xuejie, Chen Liquan, Suo Liumin
Beijing Advanced Innovation Center for Materials Genome Engineering, Key Laboratory for Renewable Energy, Beijing Key Laboratory for New Energy, Material and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, 100190, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2021 Aug 2;60(32):17547-17555. doi: 10.1002/anie.202103303. Epub 2021 Jun 23.
The high weight fraction of the electrolyte in lithium-sulfur (Li-S) full cell is the primary reason its specific energy is much below expectations. Thus far, it is still a challenge to reduce the electrolyte volume of Li-S batteries owing to their high cathode porosity and electrolyte depletion from the Li metal anode. Herein, we propose an ultralight electrolyte (0.83 g mL ) by introducing a weakly-coordinating and Li-compatible monoether, which greatly reduces the weight fraction of electrolyte within the whole cell and also enables Li-S pouch cell functionality under lean-electrolyte conditions. Compared to Li-S batteries using conventional counterparts (≈1.2 g mL ), the Li-S pouch cells equipped with our ultralight electrolyte could achieve an ultralow electrolyte weight/capacity ratio (E/C) of 2.2 g Ah and realize a 19.2 % improvement in specific energy (from 329.9 to 393.4 Wh kg ) under E/S=3.0 μL mg . Moreover, more than 20 % improvement in specific energy could be achieved using our ultralight electrolyte at various E/S ratios.
锂硫（Li-S）全电池中电解质的高重量分数是其比能量远低于预期的主要原因。迄今为止，由于Li-S电池的高阴极孔隙率以及锂金属阳极的电解质耗尽，降低其电解质体积仍然是一项挑战。在此，我们通过引入一种弱配位且与锂兼容的单醚，提出了一种超轻电解质（0.83 g·mL⁻¹），这大大降低了整个电池内电解质的重量分数，并且还能使Li-S软包电池在贫电解质条件下具备功能。与使用传统电解质（≈1.2 g·mL⁻¹）的Li-S电池相比，配备我们的超轻电解质的Li-S软包电池可实现2.2 g·Ah的超低电解质重量/容量比（E/C），并在E/S = 3.0 μL·mg⁻¹的条件下使比能量提高19.2%（从329.9提高到393.4 Wh·kg⁻¹）。此外，使用我们的超轻电解质，在各种E/S比率下比能量均可提高20%以上。
