The search for anode materials with high performance and low cost for lithium-ion batteries (LIBs) remains challenging. Herein, Earth-abundant and acid-resistant jarosite ultrathin KFe₃(SO₄)₂(OH)₆@rGO (KFN@rGO) nanosheets were fabricated via a facile and scalable hydrothermal route without any surfactant. When serving as an anode material for LIBs, KFN@rGO delivers excellent lithium storage performances, including high reversible capacity (913 mA h g⁻¹ at 20 mA g⁻¹) and robust cycling life (545 mA h g⁻¹ at the end of 1000 cycles at 500 mA g⁻¹). Moreover, the pseudocapacitive contribution is as high as 62.7% at 1 mV s⁻¹ as revealed by cyclic voltammetry. The robust cycling stability can be attributed to the hybrid structure of ultrathin KFe₃(SO₄)₂(OH)₆ nanosheets and flexible rGO which not only enhances the conductivity and structural integrity, but also induces the pseudocapacitive effect during the cycles. This work may provide an effective route to improve the electrochemical performances of other jarosite minerals through the introduction of the pseudocapacitive contribution.

中文翻译：

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黄铁矿超薄KFe ₃（SO ₄）₂（OH）₆ @rGO纳米片杂化复合材料的制备，具有拟电容性，可作为锂离子电池的坚固阳极†

寻找用于锂离子电池（LIB）的高性能和低成本阳极材料仍然具有挑战性。在此，通过简便且可扩展的水热途径在没有任何表面活性剂的情况下制备了富含地球和耐酸的黄铁矿超薄KFe ₃（SO ₄）₂（OH）₆ @rGO（KFN @ rGO）纳米片。当用作LIBS阳极材料投放，KFN @ RGO提供出色的锂存储性能，包括高的可逆容量（913毫安汞柱^-1在20mA克^-1）和稳健的循环寿命（545毫安汞柱^-1在1000年底500 mA g ^-1时的循环）。此外，如通过循环伏安法所揭示的，在1 mV s ^-1时，假电容贡献高达62.7％。鲁棒的循环稳定性可归因于超薄KFe ₃（SO ₄）₂（OH）₆纳米片和柔性rGO的混合结构，这不仅增强了导电性和结构完整性，而且在循环过程中还诱发了假电容效应。这项工作可能会提供一种有效的途径，通过引入拟电容性贡献来改善其他黄钾铁矾矿物的电化学性能。