Potassium ion batteries (PIBs) have aroused intensive research interest owing to their abundant source, low cost, and suitable working potential. Here, a V₂C-VO₂ nanoribbon intertwined nanosheet 3D multi-heterostructure with rich heterointerface and heterojunction is fabricated via a facile solution-based method for realizing a highly flexible and robust anode material of PIBs. The co-existence of V₂C-VO₂ in the constituent individual nanoribbon and nanosheet generates rich heterojunctions and heterointerfaces in this hetero-dimensional and multi-scale heterostructure, which not only constructs interconnected 3D channels for rapid electron/ion transfer and diffusion, but also greatly enhances the structural durability and mechanical robustness. With experimental results and systematical theoretical studies, it is confirmed that the V₂C-VO₂ multi-heterostructure can self-regulate the spin polarization density of constituent individual V₂C and VO₂, which propels the K⁺ ion diffusion kinetics during charge and discharge processes. Consequently, the multi-heterostructure-based electrode can maintain a capacity of ≈200 mAh g⁻¹ over repeated 2000 cycles at 1 A g⁻¹. Practically, the flexible full cells exhibit decent electrochemical property under intensive bending conditions, holding great promise for flexible electronic devices.

中文翻译：

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自旋极化密度的自调节推动柔性钾离子电池的离子扩散动力学

钾离子电池（PIBs）因其来源丰富、成本低廉、工作潜力大而引起了广泛的研究兴趣。在这里，通过基于溶液的简便方法制备了具有丰富异质界面和异质结的V ₂ C-VO ₂纳米带交织纳米片3D多异质结构，以实现高度灵活和坚固的PIB阳极材料。_{V 2} C-VO ₂共存在组成的单个纳米带和纳米片中，在这种异维和多尺度异质结构中产生了丰富的异质结和异质界面，不仅构建了互连的3D通道，用于快速电子/离子转移和扩散，而且大大提高了结构的耐久性和机械鲁棒性。通过实验结果和系统的理论研究，证实了V ₂ C-VO ₂多异质结构可以自我调节组成个体V ₂ C 和VO ₂的自旋极化密度，从而推动K ⁺充电和放电过程中的离子扩散动力学。因此，基于多异质结构的电极可以在 1 A g ^-1下重复 2000 次循环后保持≈ 200 mAh g ^-1的容量。实际上，柔性全电池在强烈弯曲条件下表现出良好的电化学性能，为柔性电子设备提供了广阔的前景。