Department of Radiation Science and Technology, Delft University of Technology, Delft, 2629JB, Netherlands.
State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
Nat Commun. 2023 Jan 27;14(1):440. doi: 10.1038/s41467-023-36075-1.
High-entropy alloys/compounds have large configurational entropy by introducing multiple components, showing improved functional properties that exceed those of conventional materials. However, how increasing entropy impacts the thermodynamic/kinetic properties in liquids that are ambiguous. Here we show this strategy in liquid electrolytes for rechargeable lithium batteries, demonstrating the substantial impact of raising the entropy of electrolytes by introducing multiple salts. Unlike all liquid electrolytes so far reported, the participation of several anionic groups in this electrolyte induces a larger diversity in solvation structures, unexpectedly decreasing solvation strengths between lithium ions and solvents/anions, facilitating lithium-ion diffusivity and the formation of stable interphase passivation layers. In comparison to the single-salt electrolytes, a low-concentration dimethyl ether electrolyte with four salts shows an enhanced cycling stability and rate capability. These findings, rationalized by the fundamental relationship between entropy-dominated solvation structures and ion transport, bring forward high-entropy electrolytes as a composition-rich and unexplored space for lithium batteries and beyond.
高熵合金/化合物通过引入多种成分获得大的构型熵，表现出超过传统材料的改善的功能特性。然而，增加熵如何影响液体的热力学/动力学性质尚不清楚。在这里，我们在可充电锂电池的液体电解质中展示了这一策略，证明了通过引入多种盐来提高电解质熵的显著影响。与迄今为止报道的所有液体电解质不同，这种电解质中几种阴离子基团的参与导致溶剂化结构的更大多样性，出人意料地降低了锂离子和溶剂/阴离子之间的溶剂化强度，促进了锂离子的扩散和稳定的相间钝化层的形成。与单盐电解质相比，具有四种盐的低浓度二甲醚电解质表现出增强的循环稳定性和倍率性能。这些发现通过熵主导的溶剂化结构和离子输运之间的基本关系得到了合理化，为锂电池及其他领域提出了高熵电解质作为一个组成丰富且尚未开发的空间。
