The quaternary alkyl ammonium (QAA) cation storage behavior of the graphite negative electrode in graphite/activated carbon (AC) is closely related to the formation of graphite intercalation compounds (GICs) during the charge and discharge process. In this work, spiro-(1,1′)-bipyrrolidinium tetrafluoroborate (SBPBF₄) and tetrahexyl ammonium tetrafluoroborate (THABF₄) dissolved in propylene carbonate (PC) were applied in graphite/AC capacitors. In situ X-ray diffraction and step-by-step QAA cation storage measurements displayed that both cations could take part in the formation of GICs, leading to the formation of a new type of GIC. Accordingly, the graphite/AC capacitor shows a satisfactory cycle performance. Moreover, the influence factor of the hierarchical and convergent intercalation behavior of mixed QAA cations was discussed in detail.

中文翻译：

---

四己基铵和螺联吡咯烷鎓阳离子会聚嵌入碳酸丙烯酯石墨电极中


石墨负极在石墨/活性炭（AC）中的季烷基铵（QAA）阳离子储存行为与充放电过程中石墨插层化合物（GIC）的形成密切相关。在这项工作中，将溶解在碳酸丙烯酯（PC）中的螺-（1,1'）-联吡咯烷鎓四氟硼酸盐（SBBPF ₄ ）和四己基四氟硼酸铵（THABF ₄ ）应用于石墨中/交流电容器。原位X射线衍射和逐步QAA阳离子存储测量表明，两种阳离子都可以参与GIC的形成，从而形成新型GIC。因此，石墨/AC电容器表现出令人满意的循环性能。此外，还详细讨论了混合QAA阳离子分层和收敛插层行为的影响因素。