Designing g‐C₃N₄/N‐Rich Carbon Fiber Composites for High‐Performance Potassium‐Ion Hybrid Capacitors

Abstract

Potassium‐based energy storage devices (PEDS) are considered as hopeful candidates for energy storage applications because of the abundant potassium resources in nature and high mobility in the electrolyte. although carbon materials show great potential for potassium‐ion storage, poor rate performance, and unsatisfactory cycle lifespan in existing carbon‐based PIBs anode, it also cannot match the dynamics and stability of the capacitor cathode. Nitrogen doping has been proven to be a effective modification strategy to improve the electrochemical performance of carbon materials. Hence, we prepare carbon nanofibers and g‐C3N4 composites with high nitrogen contents (19.78 at%); moreover, the sum of pyrrolic N and pyridinic N is up to 59.51%. It achieves high discharge capacity (391 mAh g−1 at 0.05 A g−1), rate capacity (141 mAh g−1 at 2 A g−1), and long cycling performance (201 mAh g−1 at 1 A g−1 over 3000 cycles) when as an anode for PIBs. Furthermore, it can deliver promising discharge capacity of 132 mAh g−1 at 0 °C. Moreover, as battery anode for potassium‐ion hybrid capacitors (PIHC) device with an active carbon cathode, it delivers energy/power density (62 and 2102 W kg−1) as well as high reversible capacity (106 mAh g−1 at 1 A g−1).

Non-lithium-based metal ion capacitors: recent advances and perspectives

“…Rational structural design and heteroatom doping are efficient improvement strategies to improve the performance of carbon materials. 46 In addition, MXene, niobium-based, and titanium-based compounds are also the star materials in the investigation of anode materials because of their suitable and/or adjustable interlayer structure. 47 In multivalent ion systems, the higher charge densities of the ions may cause strong ion–electrolyte interaction, and higher desolvation energy.…”

Yolk–Shell P3‐Type K0.5[Mn0.85Ni0.1Co0.05]O2: A Low‐Cost Cathode for Potassium‐Ion Batteries

“…To alleviate the strain‐induced particle cracking and to obtain high packing density, a rational structural design for layered transition metal oxides is needed for PIB cathodes. [ 17‐22 ] In the case of this, we draw inspiration from the lithium‐ion batteries (LIBs). For examples, Amine et al .…”

Engineered Polymeric Carbon Nitride Additive for Energy Storage Materials: A Review

“…prepared carbon nanofibers and PCN composites using simple electrospinning followed by calcination strategy, as depicted in Figure a. [ 132 ] The corresponding SEM image shown in Figure 11b demonstrated the representative electrospinning nanofiber structures with diameter of ≈450 nm. It should be noted that the pyridinic N and pyrrolic N contents was up to 59.51% in total N content, which are vital factors for enhancing electrochemical performance.…”

“…a–c) Reproduced with permission. [ 132 ] Copyright 2020, Wiley‐VCH. d–g) Reproduced with permission.…”