Facile Fabrication of Nitrogen‐Doped Porous Carbon as Superior Anode Material for Potassium‐Ion Batteries

Abstract

Potassium‐ion batteries (PIBs), using carbon materials as the anode, are regarded as a promising alternative to lithium‐ion batteries owing to the feasible formation of stage‐1 potassium intercalation compounds (KC8). However, due to the large radius of the potassium ion, graphite‐based electrodes still suffer poor rate capability and insufficient cycling life. In this work, a hierarchically nitrogen‐doped porous carbon (NPC) is reported for the first time. The NPC electrode delivers a high reversible capacity of 384.2 mAh g−1 after 500 cycles at a current density of 0.1 A g−1 and an outstanding rate capability of 185 mAh g−1 at 10.0 A g−1, which surpasses most of the reported carbonaceous electrodes in PIBs. The excellent performance can be ascribed to the surface‐driven behavior dominated K‐storage mechanism, which is verified by quantitative kinetics analysis. Theoretical simulation results further illuminate the enhanced K affinity in N‐doped active sites, which accounts for the superior rate performance of the NPC electrode. In addition, galvanostatic intermittent titration technique measurements further quantify the diffusion coefficient of K ions. Considering the superior electrochemical performance of the electrode and comprehensive investigation of the K storage mechanism, this work can provide fundamental references for the subsequent research of potassium‐ion batteries.

Fast Redox Kinetics in Bi‐Heteroatom Doped 3D Porous Carbon Nanosheets for High‐Performance Hybrid Potassium‐Ion Battery Capacitors

“…

instance, lithium-ion hybrid capacitors (LIHCs) consisting of an activated carbon (AC) cathode and a prelithiated graphite anode have been successfully commercialized and widely applied in small portable electronics. To date, various electrode materials, such as carbonaceous materials, [5] metal alloys, [6] oxides, [7] sulfides, [8] and MXene, [9] have been extensively studied as battery-type anodes. As a new class of hybrid capacitors, potassium-ion hybrid capacitors (PIHCs) show great potential as alternative to LIHCs due to the profusion and low cost of potassium resources.

…”

“…As a new class of hybrid capacitors, potassium-ion hybrid capacitors (PIHCs) show great potential as alternative to LIHCs due to the profusion and low cost of potassium resources. [5] Heteroatom-doped carbonbased materials have exhibited the enhanced electrochemical properties for potassium-ion storage due to the increased electric conductivity and more active sites for potassium-ion storage by generating extrinsic defects. [4] Unfortunately, the relatively large radius of K + (1.38 Å) tends to behave sluggish redox reaction kinetics for most of potassium-ion batteries (PIBs) anodes.…”

Constructing Multichannel Carbon Fibers as Freestanding Anodes for Potassium‐Ion Battery with High Capacity and Long Cycle Life

“…Figure 3a reveals that there are 8.3% N atom and 10.9% O atom, deriving from carbonization of PAN, doped in the MCCF-2 sample. [28,31,32] Among them, relative ratios of N-6 and N-5 are 40.5% and 39.4%, respectively. [28,31,32] Among them, relative ratios of N-6 and N-5 are 40.5% and 39.4%, respectively.…”

Nature of Bimetallic Oxide Sb2MoO6/rGO Anode for High‐Performance Potassium‐Ion Batteries

“…[1][2][3][4][5] Because of the natural abundance of potassium, a similar redox potential of potassium to lithium, and the low cost, potassiumion batteries (KIBs) serve as a promising substitution to LIBs, [6][7][8][9][10][11] especially attractive in the largescale energy storage systems which strive intensively to lower the price to be competitive with other energy storage techniques. which are being explored vigorously but yield a relatively low specific capacity, [17][18][19][20][21][22][23][24][25][26][27] metal oxides, such as iron oxides, [28] molybdenum oxides, [29,30] niobium pentoxides, [31] tin oxides, [32] and titanium oxides, [33] are interesting anode candidates considering their high gravimetric and volumetric specific capacity, which are able to provide high performance anodes for KIBs. [12][13][14][15][16] Therefore, searching for the high performance KIBs anode (a critical component of KIBs) to alleviate the dramatic volume change is highly demanded to build high performance KIBs.…”

“…which are being explored vigorously but yield a relatively low specific capacity, [17][18][19][20][21][22][23][24][25][26][27] metal oxides, such as iron oxides, [28] molybdenum oxides, [29,30] niobium pentoxides, [31] tin oxides, [32] and titanium oxides, [33] are interesting anode candidates considering their high gravimetric and volumetric specific capacity, which are able to provide high performance anodes for KIBs. which are being explored vigorously but yield a relatively low specific capacity, [17][18][19][20][21][22][23][24][25][26][27] metal oxides, such as iron oxides, [28] molybdenum oxides, [29,30] niobium pentoxides, [31] tin oxides, [32] and titanium oxides, [33] are interesting anode candidates considering their high gravimetric and volumetric specific capacity, which are able to provide high performance anodes for KIBs.…”