半固态钠钾合金负极构建钠金属电池电极-电解质共形界面OA北大核心CSTPCD
Designing Conformal Electrode-electrolyte Interface by Semi-solid NaK Anode for Sodium Metal Batteries
以低成本、高安全性、高能量密度著称的固态钠金属电池(SSNBs)在下一代可充电电池中具有重要的地位.然而,固态电解质亟待改善的界面接触问题一直阻碍着SSNBs走向商业化.本研究以电极-电解质界面设计为出发点,采用钠钾合金(NaK)和碳纳米管制备了半固态NaK合金电极(NKC).与Na电极不同,可涂覆的浆料状NKC电极在集流体和凝胶电解质上具有较好的粘附性和界面相容性,构建了紧密接触的电极-电解质界面.此外,通过引入SiO2作为无机填料,改善了NaK合金在凝胶聚合物电解质上的润湿性,进一步实现了共形接触的界面.因此,NKC对称电池在300 h的长循环下的过电位远小于Na对称电池,匹配Na3V3(PO4)2正极的全电池具有106.8 mAh·g-1的首次放电容量,300圈容量保持率为89.61%,即使在10 C的高倍率下放电容量仍有88.1 mAh·g-1.出色的电化学性能凸显了NKC电极良好的应用潜力.
Solid-state Na metal batteries (SSNBs),known for its low cost,high safety,and high energy density,hold a significant position in the next generation of rechargeable batteries.However,the urgent challenge of poor interfacial contact in solid-state electrolytes has hindered the commercialization of SSNBs.Driven by the concept of intimate electrode-electrolyte interface design,this study employs a combination of NaK alloy and carbon nanotubes to prepare a semi-solid NaK (NKC) anode.Unlike traditional Na anodes,the paintable paste-like NKC anode exhibits superior adhesion and interface compatibility with both current collectors and gel electrolytes,significantly enhancing the intimate contact of electrode-electrolyte interface.Additionally,the filling of SiO2 nanoparticles improves the wettability of NaK alloy on gel polymer electrolytes,further achieving a conformal interface contact.Consequently,the overpotential of the NKC symmetric cell is markedly lower than that of the Na symmetric cell when subjected to a long cycle of 300 h.The full cell coupled with Na3V2(PO4)2 cathodes had an initial discharge capacity of 106.8 mAh·g-1 with a capacity retention of 89.61% after 300 cycles,and a high discharge capacity of 88.1 mAh·g-1 even at a high rate of 10 C.The outstanding electrochemical performance highlights the promising application potential of the NKC electrode.
尹春森;陈泽远;王秀丽
浙江大学材料科学与工程学院,浙江杭州 310058
固态钠金属电池钠钾合金凝胶电解质电极-电解质界面无枝晶负极
Solid-state Na metal batteryNaK alloyGel electrolyteelectrode-electrolyte interfacedendrite free anode
《材料科学与工程学报》 2024 (004)
533-543 / 11
National Natural Science Foundation of China(52073253)
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