Constructing electrode materials with fast ions and electrons transport channels is an effective solution to achieve high-power-density and longcycle potassium-ion batteries (PIBs). Herein, completely opening radial pores in N/O dual-doped carbon nanospheres (RPCNSs) are constructed as anode for high-power PIBs. The RPCNS with hierarchical structure (micro/ meso/macropores and radial channels) and N/O dual-doping permits speedy ions and electrons transportation within the carbon nanospheres anode, achieving a reversible capacity of 346 mAh g −1 at 50 mA g −1 after 360 cycles and long-term cycling life over 2000 cycles without obvious capacity attenuation. The in situ Raman and kinetic analysis (in situ electrochemical impedance spectroscopy and galvanostatic intermittent titration) suggest that the exquisitely designed pore structure and heterodoping enable highly reversible electrochemical reaction and fast de/ intercalation kinetics. Moreover, the full cells packaged with RPCNS anode can be fully charged in 10 s and exhibit the highest charge power density of 24 866 W kg −1 and longest cycling endurance of 5000 cycles in reported PIBs. The unique structural engineering provides a new way for high-power density potassium-ion storage devices.

Lithium sulfur (Li–S) batteries have attracted considerable interest as next‐generation high‐density energy storage devices. However, their practical application is limited by low capacity and rapid capacity fading at commerical‐level mass loadings, which is largely attributed to the inferior electron/ion conduction, as well as severe the shuttling effect of soluble polysulfide species. To address these issues, a three‐dimensional holey graphene/polyacrylonitrile sulfur (3DHG/PS) composite cathode is developed for high‐mass‐loading Li–S batteries. The unique architectural design with the 3D holey graphene framework ensures fast electron and ion transport within the thick electrode, and affords enough space for mitigating the volume expansion of the electrode. Moreover, in situ Raman results demonstrate that covalent sulfur within 3DHG/PS fundamentally avoids forming soluble lithium polysulfides, which effectively reduces the undesired shuttling effect. With these advantages, the 3DHG/PS cathode exhibits an ultra‐low capacity fading rate of 0.012% per cycle after continuous 1500 cycles, as well as high specific capacity and superior rate capability with a high mass loading of 15.2 mg cm–2, which offers a promising avenue to construct future Li–S batteries with superior performance at mass loadings that exceed commercial levels.

Potassium-ion hybrid capacitors (KIHCs) have attracted increasing research interest because of the virtues of potassium-ion batteries and supercapacitors. The development of KIHCs is subject to the investigation of applicable K+ storage materials which are able to accommodate the relatively large size and high activity of potassium. Here, we report a cocoon silk chemistry strategy to synthesize a hierarchically porous nitrogen-doped carbon (SHPNC). The as-prepared SHPNC with high surface area and rich N-doping not only offers highly efficient channels for the fast transport of electrons and K ions during cycling, but also provides sufficient void space to relieve volume expansion of electrode and improves its stability. Therefore, KIHCs with SHPNC anode and activated carbon cathode afford high energy of 135 Wh kg−1 (calculated based on the total mass of anode and cathode), long lifespan, and ultrafast charge/slow discharge performance. This study defines that the KIHCs show great application prospect in the field of high-performance energy storage devices.

Potassium-ion batteries (PIBs) are of academic and economic significance, but still limited by the lack of highly active electrode materials for de-/intercalation of large-radius K ions. Herein, an interconnected nitrogen/sulfur co-doped carbon nanosheep bundle (N/S-CSB) was proposed as the potassium ions storage material. The rich co-doping of nitrogen/sulfur of N/S-CNB with three-dimensional hierarchical bundled array structure yields distensible interlayer spaces to buffer the volume expansion during K + insertion/extraction, offers more electrochemical active sites to obtain a high specific capacity, and provides efficient channels for fast ion/electron transports. Therefore, the N/S-CSB anode achieved high reversible specific capacity of 365 mAh/g obtained at 50 mA/g after 200 cycles with a coulombic efficiency (CE) close to 100%, high rate performance and long cycle stability. Moreover, the in-situ Raman spectra indicated outstanding reaction kinetics of as-prepared N/S-CSB anode.

Potassium-ion hybrid capacitors (KIHCs) have attracted growing attention due to the natural abundance and low cost of potassium. However, KIHCs are still limited by sluggish redox reaction kinetics in electrodes during the accommodation of large-sized K+. Herein, a starch-derived hierarchically porous nitrogen-doped carbon (SHPNC) anode and active carbon cathode were rationally designed for dual-carbon electrode-based KIHCs with high energy density. The hierarchical structure and rich doped nitrogen in the SHPNC anode result in a distensible interlayer space to buffer volume expansion during K+ insertion/extraction, offers more electrochemical active sites to achieve high specific capacity, and has highly efficient channels for fast ion/electron transports. The in situ Raman and ex situ TEM demonstrated a reversible electrochemical behavior of the SHPNC anode. Thus, the SHPNC anode delivers superior cycling stability and a high reversible capacity (310 mA h g–1 at 50 mA g–1). In particular, the KIHCs assembled by the SHPNC anode and commercial active carbon cathode can deliver a high energy density of 165 W h kg–1 at a current density of 50 mA g–1 and an ultra-long cycle life of 10,000 cycles at 1 A g–1 (calculated based on the total mass of the anode and cathode).