Potassium ion anode versus sodium ion anode: Potato starch residue derived carbon material as a case study

Abstract Herein, potato starch residue derived carbon materials (PSRC) and KOH activated PSRC (denoted as APSRC) are successfully realized in this work. Interestingly, it is found that PSRC shows better electrochemical performance in potassium ion batteries (KIBs) than in sodium ion batteries (NIBs)...
Ausführliche Beschreibung

Abstract Herein, potato starch residue derived carbon materials (PSRC) and KOH activated PSRC (denoted as APSRC) are successfully realized in this work. Interestingly, it is found that PSRC shows better electrochemical performance in potassium ion batteries (KIBs) than in sodium ion batteries (NIBs); however, the APSRC exhibits more excellent performance in NIBs than in KIBs. It is worth noting that the surface area and pore volume might be essential to $ Na^{+} $/$ K^{+} $ storage. For the PSRC with relatively lowered surface area and pore volome, the diffusion-controlled process is the main storage mode in NIBs. Nevertheless, the surface charge storage process is the main storage way for the PSRC in KIBs. On the other hand, the APSRC possesses large ratio of surface-dominated contribution to the whole capacity in NIBs and KIBs, which could be attributed to the more active sizes because of the larger surface area and higher pore volume. Furthermore, based on the optimal performance of APSRC in SIBs, sodium ion capacitors (NICs) utilizing APSRC as both cathode and anode materials are assembled. This NICs demonstrate satisfied performance with the energy density of 76.4 Wh $ kg^{−1} $ at the power density of 150 W $ kg^{−1} $. Ausführliche Beschreibung