Black phosphorus (BP) has received increasing research attention as an anode material in sodium ion batteries (SIBs) due to its high capacity, electronic conductivity and chemical stability. However, it is still challenging for BP based SIB anodes to achieve a high electrochemical performance utilizing cost-effective materials and synthetic methods. This work presents a sodium ion anode based on a facile BP -carbon nanocomposite synthesized from commercial red phosphorus and low-cost super P carbon black. Intimate interactions between BP and carbon are present which help to maintain the electrical conduction during cycling and therefore a high cycling stability is achieved. It exhibits a high capacity retention of 1381 mAh g -1 for sodium ion storage after 100 cycles, maintaining 90.5 % of the initial reversible capacity. Such high performance / materials cost ratio may provide direction for future phosphorus based anodes in high energy density SIBs.Cost-effective and high energy density batteries and battery materials are required to meet the demand of electricity storage. Sodium ion batteries (SIBs) attract increasing research attention because of the high abundance of sodium compared to lithium, and significant progress has been made in recent years. [1][2][3] Among the high-capacity anode materials (Sb, Sn, etc.) for sodium ion storage, phosphorus exhibits the highest theoretical capacity of 2596 mAh g −1 (Na 3 P). Significant research interest has been triggered by the prospects of high energy density SIBs based on phosphorus anodes. [4,5] Phosphorus exists in several allotropes that exhibit strikingly different properties. White phosphorus is chemically unstable, volatile, toxic and non-conducting, and therefore not suitable for battery applications. The most common allotrope, red phosphorus, is widely available and chemically stable, and has been studied intensively for sodium ion batteries. [6][7][8][9][10][11][12][13] However, its low electrical conductivity appears to be a major drawback. To address this issue, these electrodes included a large amount of costly carbon nanomaterials (graphene, carbon nanotube (CNT), carbon nanofiber (CNF), etc.). For large scale applications the use of CNT's needs orders of magnitude reduced cost levels, [14] while also graphene and its processing are considered costly. [15] With respect to energy density and manufacturing cost these material factors [16] form a barrier for the commercial introduction of phosphorus as the anode materials for SIBs. Cost-effective super P carbon black are also investigated, [17] but the cycle life of the electrode (only 30 de-/sodiation cycles were reported) is still to be improved.The use of carbon should be noted because carbon and phosphorus do not form binary inorganic or molecular compounds; they can, however, form composites of phosphorus and carbon nanostructures held together by what will likely be weak van der Waals forces. The fact that no P-C compounds are stable implies that upon Na insertion and extraction there are...