Due to the high theoretical capacity and open frameworks, the low-cost sodium iron pyrophosphate Na_3.12Fe_2.44(P₂O₇)₂ has become a promising candidate for cathode materials of the sodium ion batteries (SIBs). However, NFPO is very sensitive to moisture and CO₂, which causes serious surface oxidation reaction and results in degraded high-rate charge/discharge performance and cyclic stability. Herein, we developed a seaweed-derived synthesis strategy to prepare air stable NFPO/r-GO aerogels by using sodium alginate (SA) and reduced graphene oxide (r-GO) as precursors. X-ray photoelectron spectroscopy (XPS) proved that there were no residual Na species on the surface of prepared NFPO/r-GO aerogels and no any oxidized impurities after exposing in air for 100 days. When evaluating the NFPO/r-GO aerogels as cathode materials for SIBs, the sample exhibits excellent reversible capacity of 116.1 mAh g⁻¹ at 0.1 C, 88.82% capacity retention after 5000 cycles and superior rate capacity of 72.3 mAh g⁻¹ at 20 C. The superior electrochemical performances are mainly attributed the delicate structure, which can not only increase the electronic conductivity, but also improve air stability of NFPO by suppressing surface side reactions with moisture and CO₂.

由于高理论容量和开放框架，低成本的焦磷酸钠铁Na _3.12 Fe _2.44（P ₂ O ₇）₂已成为钠离子电池（SIB）阴极材料的有希望的候选者。但是，NFPO对水分和CO ₂非常敏感，这会引起严重的表面氧化反应，并导致高倍率的充放电性能和循环稳定性下降。本文中，我们开发了一种海藻衍生的合成策略，以藻酸钠（SA）和还原型氧化石墨烯（r-GO）为前体来制备空气稳定的NFPO / r-GO气凝胶。X射线光电子能谱（XPS）证明，制备的NFPO / r-GO气凝胶表面暴露于空气中100天后，没有残留的Na物质，也没有氧化的杂质。当评估NFPO / r-GO气凝胶作为SIBs的阴极材料时，样品在0.1 C时具有116.1 mAh g ^-1的优异可逆容量，在5000次循环后显示88.82％的容量保持率，以及72.3 mAh g ^-1的倍率容量优异的电化学性能主要归因于其精细的结构，该结构不仅可以提高电子电导率，而且还可以通过抑制与水分和CO _2的表面副反应来提高NFPO的空气稳定性。