Graphitic Carbon Nanocage as a Stable and High Power Anode for Potassium‐Ion Batteries

Abstract

As an emerging electrochemical energy storage device, potassium-ion batteries (PIBs) have drawn growing interest due to the resource-abundance and low cost of potassium. Graphite-based materials, as the most common anodes for commercial Li-ion batteries, have a very low capacity when used an anode for Na-ion batteries, but they show reasonable capacities as anodes for PIBs. The practical application of graphitic materials in PIBs suffers from poor cyclability, however, due to the large interlayer expansion/ shrinkage caused by the intercalation/deintercalation of potassium ions. Here, a highly graphitic carbon nanocage (CNC) is reported as a PIBs anode, which exhibits excellent cyclability and superior depotassiation capacity of 175 mAh g-1at 35 C. The potassium storage mechanism in CNC is revealed by cyclic voltammetry as due to redox reactions (intercalation/deintercalation) and double-layer capacitance (surface adsorption/desorption). The present results give new insights into structural design for graphitic anode materials in PIBs and understanding the double-layer capacitance effect in alkali metal ion batteries.

K‐Ion Storage Enhancement in Sb2O3/Reduced Graphene Oxide Using Ether‐Based Electrolyte

“…After calculation, the GITT values of Sb 2 O 3 , Sb 2 O 3 -RGO, and RGO are shown in Figure 7f-i. These peak shifts are attributed to the contribution of capacitive behavior, and the relationship are calculated between peak current (i) and scan rate (v) as follows: [52] = I av b (2) Adv. Such high D K+ of Sb 2 O 3 -RGO electrode can remarkable accelerate the diffusion of K-ion, which is helpful to improve their electrochemical performance for K-ion storage.…”

Localized High‐Concentration Electrolytes Boost Potassium Storage in High‐Loading Graphite

“…[3,17] In 2015, Ji and Hu have separately demonstrated the electrochemical intercalation of K ions into graphite in potassium hexafluorophosphate (KPF 6 )/ ethylene carbonate (EC)-diethyl carbonate (DEC) electrolytes. [3,17] In 2015, Ji and Hu have separately demonstrated the electrochemical intercalation of K ions into graphite in potassium hexafluorophosphate (KPF 6 )/ ethylene carbonate (EC)-diethyl carbonate (DEC) electrolytes.…”

“…2019, 9,1902618 (Figure 3b). [3] For the HCE, the graphite also delivers an excellent depotassiation rate capability with a high reversible capacity of 127 mAh g −1 at 4.5 C, i.e., the capacity retention reaches 84.7% of that at 0.025 C (150 mAh g −1 ) ( Figure S10, Supporting Information). The rate capability of graphite was further evaluated in Figure 3c.…”

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.…”