Sodium ion batteries (NIBs) have gradually become an alternative to lithium ion batteries. Prussian blues (PBs) are regarded as a promising kind of cathode materials for NIBs, but their poor electrical conductivity has always been a considerable issue limiting its performance. In our work, we have optimized the PB cathode by utilizing reduced graphene oxide (RGO) as the conductive additive, whose performance is much higher than that of PB cathode with conventional conductive Super P. After optimization, our PB cathode with RGO additive delivers a reversible specific capacity of 80 mAh g^-1 at 50 mA g^-1 after 200 cycles without obvious attenuation. We also adopt current images and distribution of relaxation time technology to further analyze the reasons of electrochemical performance improvement. It is found that RGO conductive additive can remarkably enhance the intensity and uniformity of current in the electrode. We believe our work will provide new insights into the field of NIBs.

钠离子电池（NIB）已逐渐成为锂离子电池的替代品。普鲁士蓝（PBs）被认为是用于NIB的一种有前途的阴极材料，但是它们不良的电导率一直是限制其性能的重要问题。在我们的工作中，我们通过使用还原型氧化石墨烯（RGO）作为导电添加剂优化了PB阴极，其性能远高于具有传统导电Super P的PB阴极。经过优化，我们的带有RGO添加剂的PB阴极可提供80毫安克可逆比容量^-1在50mA克^-1200个周期后没有明显衰减。我们还采用当前图像和弛豫时间技术分布来进一步分析电化学性能改善的原因。发现RGO导电添加剂可以显着提高电极中电流的强度和均匀性。我们相信我们的工作将为NIB领域提供新的见解。