Jiang Cheng, Gu Yuming, Tang Mi, Chen Yuan, Wu Yanchao, Ma Jing, Wang Chengliang, Hu Wenping
School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China.
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):10461-10470. doi: 10.1021/acsami.9b21993. Epub 2020 Feb 20.
Li has been regarded as the most attractive anode for next-generation high-energy-density batteries due to its high specific capacity and low electrochemical potential. However, its low electrochemical potential leads to the side reaction of Li with the solvent of the electrolyte (the solvation of Li ions exacerbates the reaction). This adverse side reaction results in uneven Li distribution and deposition, low Coulombic efficiency, and the formation of Li dendrites. Herein, we demonstrate an efficient method for achieving successive desolvation and homogeneous distribution of Li ions by using a double-layer membrane. The first layer is designed to enable the desolvation of Li ions. The second layer with controllable and ordered nanopores is expected to facilitate the homogeneous and exclusive transport of Li ions. The efficiency of the double-layer membrane on desolvation and exclusive transport of Li ions is confirmed by theoretical calculations, the significantly enhanced Li-ion transference number, improved Coulombic efficiency, and the inhibition of Li dendrites. These results will deepen our understanding of the modulation of ions and pave a way to the next-generation high-energy-density Li-metal batteries.
由于锂具有高比容量和低电化学势，它被认为是下一代高能量密度电池最具吸引力的负极材料。然而，其低电化学势会导致锂与电解质溶剂发生副反应（锂离子的溶剂化会加剧该反应）。这种不利的副反应会导致锂分布和沉积不均匀、库仑效率低以及锂枝晶的形成。在此，我们展示了一种通过使用双层膜实现锂离子连续去溶剂化和均匀分布的有效方法。第一层旨在实现锂离子的去溶剂化。具有可控且有序纳米孔的第二层有望促进锂离子的均匀且排他性传输。双层膜对锂离子去溶剂化和排他性传输的效率通过理论计算、显著提高的锂离子迁移数、改善的库仑效率以及对锂枝晶的抑制得到了证实。这些结果将加深我们对离子调制的理解，并为下一代高能量密度锂金属电池铺平道路。
