NiS₂ is a promising anode material for sodium-ion batteries (SIBs) and capacitors (SICs). However, the sluggish Na⁺ diffusion and large volume change of bulk NiS₂ during sodiation/de-sodiation lead to poor rate capability and fast capacity decay, limiting its practical application. Herein, we design and prepare well-oriented NiS₂ nanosheets on porous carbon microtubes (denoted as NiS₂/pCMT) as a novel anode material for SIBs/SHCs. The unique porous hollow carbon tubes and NiS₂ nanosheets can well relieve the repeated stress/strain and maintain the structural integrity of the composite anode during long-term charging/discharging. As a confirmation, a modelled SHC is constructed by using the NiS₂/pCMT composite as anode and coupling with an activated carbon cathode, delivering a high energy density of 136 Wh kg⁻¹ and good cycling stability. The first-principles density functional theory (DFT) calculations confirm that the NiS₂ nanosheets surface has a high chemical affinity towards Na⁺ ions, promising the concentration of Na⁺ ion on/nearby the surface for fast redox reactions during sodiation/de-sodiation of NiS₂. This work provides some new insights for the design and fabrication novel composite electrode materials for applications in beyond lithium-ion batteries/capacitors.

NiS ₂是用于钠离子电池（SIB）和电容器（SIC）的有希望的阳极材料。但是，Na ⁺扩散缓慢以及在成泥/脱泥过程中块状NiS _2的体积变化大，导致速率能力差和容量衰减快，限制了其实际应用。本文中，我们在多孔碳微管上设计并制备了取向良好的NiS ₂纳米片（表示为NiS ₂ / pCMT），作为SIBs / SHCs的新型阳极材料。独特的多孔空心碳管和NiS ₂纳米片可以很好地缓解重复的应力/应变，并在长期充电/放电过程中保持复合阳极的结构完整性。作为确认，通过使用NiS ₂ / pCMT复合材料作为阳极并与活性炭阴极耦合，构建了模型化的SHC ，提供了136 Wh kg ^-1的高能量密度和良好的循环稳定性。第一性原理密度泛函理论（DFT）的计算证实了NiS ₂纳米片表面对Na ⁺离子具有很高的化学亲和力，从而保证了在表面上/附近Na ⁺离子的浓度，可在增盐/脱盐过程中快速进行氧化还原反应的NiS ₂。这项工作为设计和制造新型复合电极材料提供了新的见识，这些复合电极材料可用于锂离子电池/电容器以外的领域。