Sulfonylamide‐Based Ionic Liquids for High‐Voltage Potassium‐Ion Batteries with Honeycomb Layered Cathode Oxides
Sulfonylamide‐Based Ionic Liquids for High‐Voltage Potassium‐Ion Batteries with Honeycomb Layered Cathode Oxides
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DOI：
10.1002/celc.201900689
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发表时间：
2019-06
期刊：
影响因子：
4
通讯作者：
Kazuki Yoshii;T. Masese;Minami Kato;K. Kubota;Hiroshi Senoh;M. Shikano
中科院分区：
文献类型：
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作者：
Kazuki Yoshii;T. Masese;Minami Kato;K. Kubota;Hiroshi Senoh;M. Shikano
世界正处于一个新时代的前沿，可持续和高性能储能系统的发展正受到至关重要的关注。钾离子电池不仅被视为廉价的电池候选者，而且在单价阳离子化学体系中被视为倒数第二的高压储能系统。然而，由于缺乏适用于高压运行的电解质，特别是由于正极材料的有限可用性，它们的性能和可持续性受到了影响。在此，通过评估基于双（三氟甲磺酰）酰胺钾（KTFSA）的离子液体的物理化学性质，以及与新型高压层状正极材料耦合时的电化学性质，展示了其作为高压电解质的潜力。这些离子液体在钾溶解/沉积过程中表现出较低的氧化还原电位（具有约6.0 V的宽电压耐受范围），使其成为高压钾离子电池配置中可行且安全的电解质。通过将这种电解质与新型高压层状正极成分相匹配，证明了其稳定的电化学性能，从而证实了这一点。基于双（三氟甲磺酰）酰胺钾的电化学稳定离子液体的当前研究结果将促进高性能正极材料的进一步发展，这些正极材料在高压条件下的性能显然因缺乏合适且兼容的电解质而受到限制。
The world is at the cusp of a new era where pivotal importance is being attached to the development of sustainable and high-performance energy storage systems. Potassium-ion batteries are deemed not only as cheap battery candidates, but also as the penultimate high-voltage energy storage systems within the monovalent-cation chemistries. However, their performance and sustainability are undermined by the lack of suitable electrolytes for high-voltage operation particularly due to the limited availability of cathode materials. Here, the potential of ionic liquids based on potassium bis(trifluoromethanesulfonyl)amide (KTFSA) as high-voltage electrolytes is presented by assessing their physicochemical properties, along with the electrochemical properties upon coupling with new high-voltage layered cathode materials. These ionic liquids demonstrate a lower redox potential for potassium dissolution / deposition (with a wide voltage tolerance of around $6.0$ $\rm V$), placing them as feasible and safe electrolytes for high-voltage potassium-ion battery configuration. This is proven by matching this electrolyte with new high-voltage layered cathode compositions, demonstrating stable electrochemical performance. The present findings of electrochemically stable ionic liquids based on potassium bis(trifluoromethanesulfonyl)amide will bolster further advancement of high-performance cathode materials, whose performance at high-voltage regimes were apparently restricted by the paucity of suitable and compatible electrolytes.