Radial Pores in Nitrogen/Oxygen Dual‐Doped Carbon Nanospheres Anode Boost High‐Power and Ultrastable Potassium‐Ion Batteries

Abstract

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.

Reversible Oxygen-Rich Functional Groups Grafted 3D Honeycomb-Like Carbon Anode for Super-Long Potassium Ion Batteries

“…As seen in Fig. 2h, all OFGC-500/600/700 display a typical type II Remarkably, the specific surface area of OFGC increases with the rise of temperature, which is consistent with the previous literature reports [27]. High nitrogen absorption at low relative pressure indicates that OFGC has high mesopores.…”

“…Notably, O-doping can improve the wettability of the electrolyte and introduces more active sites, leading to better reaction kinetics. This has been reported in the previous literature [27]. However, whether COOH and C = O functional groups can store K + has not been studied.…”

“…Notably, the grafting of rich oxygen functional groups may increase the impedance of carbon electrodes, but can significantly improve the energy storage capacity of the carbon-based electrode, indicating that the reduction in electrode conductivity does not affect the energy storage efficiency of oxygen functional groups [25]. In addition, oxygen functional groups can also regulate the interface composition of the electrolyte by changing the physical and chemical properties of an electrode material such as defect, edge, structure, and electrical conductivity [26][27][28]. It has been reported that C = O and COOH functional groups can contribute to the formation of the highly conductive, complete, and robust inorganic SEI films [25].…”

Homologous MXene‐Derived Electrodes for Potassium‐Ion Full Batteries

“…[8][9][10] Typical design strategies such as heteroatom dopants (e.g., N, O) and edge-defect engineering in the carbonaceous matrix have been adopted to alleviate these issues to some extent. [11][12][13] One remaining dilemma resides in that deficient heteroatom dopants induce slightly improved electronic configurations (thus performance), whereas excessive sp 3 -C defects result in discrete domains with poor electron transport. As the case stands, new PIB electrode materials and judicious design strategies are needed to achieve satisfying performance.Metal-organic framework (MOF), consisting of metal ions/clusters covalently bonded with organic linkers, provides a potential carbonaceous platform for potassium ion storage.…”

A review on carbon nanomaterials for K‐ion battery anode: Progress and perspectives

“…To understand the exact mechanism, in situ Raman can be a good solution, while Raman can provide the exact information of carbon materials. 45,[284][285][286][287][288][289][290][291] For example, Yi et al 291 have confirmed by in situ Raman that their composite materials go through two different reaction mechanisms, in which the formation of K 2 Se in the first convention reaction process and K 3 Sb phase in the following alloying reaction stage during K + storage at the Sb 2 Se 3 @C microtubes. Further, Chen et al 284 have also investigated the reaction mechanism by in situ Raman, in which they observed that the Bi 2 S 3 transformed into metal bismuth and the formation of Raman peak for C S bonds at 748 cm À1 , indicating an enhanced disorder graphitization after the potassiation process.…”