Potassium-ion batteries (PIBs) are considered as potential replacements to lithium-ion batteries for large scale energy storage applications due to abundant potassium resources and low cost. However, it is a rough road to find suitable materials with high capacity and cycling stability due to the large K ion radius. In this study, a simple method, electrodeposition, is used to anchor SnO₂ nanoparticles on three dimensional carbon foam (SnO₂@CF) as a freestanding anode for PIBs. The prepared freestanding SnO₂@CF electrode features a three dimensional (3D) conductive carbon frame and SnO₂ nanoparticles, which can enhance electron transfer, prevent SnO₂ from losing electrical contact after large volume changes and facilitate electrolyte infiltration and K ion transfer. As expected, SnO₂@CF delivers a high K storage specific capacity, and outstanding cycling stability (231.7 mA h g⁻¹ after 400 cycles at 1 A g⁻¹) and rate performance (371.4, 307.6, 247.3 and 143.5 mA h g⁻¹ at 0.5, 1, 2 and 5 A g⁻¹, respectively). Meanwhile, the phase transition of the SnO₂@CF electrode is tracked during the charge and discharge processes in PIBs. This study provides a facile method to prepare freestanding electrode materials and a promising anode material for PIBs.

中文翻译：

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SnO2纳米颗粒锚固在碳泡沫上，作为高性能钾离子电池的独立阳极

由于钾资源丰富且成本低廉，钾离子电池（PIB）被认为是锂离子电池在大规模储能应用中的潜在替代品。然而，由于大的K离子半径，找到具有高容量和循环稳定性的合适材料是一条艰难的道路。在这项研究中，一种简单的电沉积方法被用来将SnO ₂纳米颗粒固定在三维碳泡沫（SnO ₂ @CF）上，作为PIB的独立阳极。制备的独立式SnO ₂ @CF电极具有三维（3D）导电碳骨架和SnO ₂纳米粒子，可以增强电子传递，防止SnO ₂避免在大体积变化后失去电接触并促进电解质渗透和钾离子转移。正如预期的那样，的SnO ₂ @CF提供高K存储比容量，和出色的循环稳定性（231.7毫安汞柱^-1 1 A G 400次循环后^-1）和倍率性能（371.4，307.6，247.3和143.5毫安汞柱^-1分别为0.5、1、2和5 A g ^-1）。同时，在PIB中的充电和放电过程中跟踪SnO ₂ @CF电极的相变。这项研究提供了一种简便的方法来制备独立式电极材料和有希望的PIB阳极材料。