An Organic Anode for High Temperature Potassium‐Ion Batteries

Abstract

exceptional battery performance is still a significant challenge at high temperatures due to the structural degradation caused by the fast transfer of alkali-ions. [4] Therefore, Li-ion batteries have been intensively investigated as high temperature batteries owing to the smallest ion size of Li among the alkali-ions. [4,5] Nevertheless, the scarcity and unevenly global distribution of Li resource is an obstacle for the further development of Li-ion batteries. [3,6] One promising strategy to replace Li-ion batteries is developing hightemperature K-ion batteries (KIBs), which have distinguished advantages among alkali-ion batteries, e.g., the significantly more abundance of K than Li (2.09 vs 0.0017 wt% in the Earth crust) and lower redox potential of K + /K than Na + /Na (−2.93 vs −2.71 V). [3,6,7] All these merits ensure KIBs provide clean energy with low cost and high energy density. However, the larger ion size of K + than Li + and Na + results in a significant structural deterioration for the conversion and intercalation electrodes. The conversion electrodes suffer from a large volume change that is tremendously significant in KIBs, [4,8,9] while the capacity of the intercalation electrodes is very low. [10,11] As reported by Amine's group, stabilizing the material surface is the key factor for cycling Li-ion batteries at high temperatures such as 55 °C. [12] Thus, it is extremely challenging for KIB electrodes to withstand a temperature above 55 °C, due to the less stable solid electrolyte interphase (SEI) compared to the Li counterpart. [13] Herein, we designed an organic anode that stores K-ions through surface reaction for high-temperature KIBs beyond the current operating temperature of 55 °C with high rate capability and long cycle life. Azobenzene-4,4′-dicarboxylic acid potassium salts (ADAPTS) with a redox center of azo group (NN) is selected to reversibly react with K + , as shown in Figure 1a. Different from the conversion and intercalation reactions, ADAPTS with surface reaction can largely retain the structural stability during the reversible electrochemical reactions between azo group and K + even at a high temperature. Furthermore, organic compounds are ideal electrode materials for clean energy applications since they are inexpensive and sustainable. [14,15] At the ambient temperature, the ADAPTS anode delivers a reversible capacity of 109 mAh g −1 at 0.1C for 100 cycles and a long-term cycle life of 1000 cycles is achievedThe wide applications of rechargeable batteries require state-of-the-art batteries that are sustainable (abundant resource), tolerant to hightemperature operations, and excellent in delivering high capacity and longterm cycling life. Due to the scarcity and uneven distribution of lithium, it is urgent to develop alternative rechargeable batteries. Herein, an organic compound, azobenzene-4,4′-dicarboxylic acid potassium salts (ADAPTS) is developed, with an azo group as the redox center for high performance potassium-ion batteries (KIBs). The extended π-conjugated structure i...

In Situ Coating Graphdiyne for High‐Energy‐Density and Stable Organic Cathodes

“…[ 7–11 ] Exploiting new organic cathode materials is still one of the primary directions in this field. [ 12–14 ] Small‐molecule organic cathodes, which can be easily crystalized with high stacking density, are the ideal materials; however, their applications are seriously hindered due to the intrinsic low conductivity and molecular dissolution ( Figure a). Without an effective coating technology, the bottleneck of overcoming these two problems cannot be really broken for organic cathodes.…”

“…It has been studied as the cathode for storing the Li + , Na + and K + , and shown attractive potential. [ 14,30,31 ] SR, featuring a six‐membered ring of carbon atoms with four carbonyl groups and a carbon−carbon double bond (Figure S2c, Supporting Information), has an orthorhombic crystalline structure, and was investigated as the promising cathodes for storing the Na + and Mg 2+ . [ 32,33 ] Their wide applications for storing different alkali metal ions demonstrate that these organic cathodes have great possibility to be used for developing the cheap and environmental‐friendly batteries.…”

Novel Insoluble Organic Cathodes for Advanced Organic K‐Ion Batteries

“…[ 4 ] Among them, potassium terephthalate (K 2 TP, 222 mAh g −1 ) and potassium 2,5‐pyridinedicarboxylate (K 2 PC, 221 mAh g −1 ) were initially unveiled as the first organic anodes in 2017; [ 5 ] and 3,4,9,10‐perylene‐tetracarboxylic dianhydride (PTCDA, 131 mAh g −1 ) was the first example of organic cathodes reported in 2015. [ 6 ] Afterward, several organic anodes (e.g., K 2 BPDC, [ 7 ] K 4 PTC, [ 8 ] ADAPTS, [ 9 ] and vitamin K [ 10 ] ) and organic cathodes (e.g., PAQS, [ 11 ] AQDS, [ 12 ] CuTCNQ, [ 13 ] PPTS, [ 14 ] HAT, [ 15 ] PI, [ 16 ] and PTCDI [ 17 ] ) were respectively reported.…”

Facile Synthesis of Ultra‐Small Few‐Layer Nanostructured MoSe2 Embedded on N, P Co‐Doped Bio‐Carbon for High‐Performance Half/Full Sodium‐Ion and Potassium‐Ion Batteries

“…Therefore, sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs), with analogical energy storage behavior to LIBs, have sparked significant attention and are considered as promising alternatives to LIBs, ascribed to their competitive cost, appropriate redox potential, along with inexhaustible sodium/potassium reserves, which can be more able to meet the urgent demands of large‐scale energy storage markets . However, the radius of Na + /K + is larger than that of Li + , which might account for high diffusion barriers and severe volume variations, leading to cyclic instability and inferior rate capability . Therefore, designing various anode composites that can provide fast kinetics and admirable charge/discharge capacities is fast becoming a pressing task.…”

“…[13][14][15][16][17][18][19][20][21] However,t he radius of Na + /K + is largert han that of Li + ,w hich mighta ccountf or high diffusion barriers and severe volumevariations, leadingt oc yclic instability and inferior rate capability. [22][23][24][25][26][27][28][29] Therefore, designing various anode composites that can provide fast kinetics and admirable charge/dischargec apacities is fast becoming ap ressing task.…”