Rational-design of polyaniline cathode using proton doping strategy by graphene oxide for enhanced aqueous zinc-ion batteries

Design Strategies for High‐Performance Aqueous Zn/Organic Batteries

“…[52][53][54][55][56] They often display bipolar-type redox chemistry in aqueous ZIBs.Inthe case of Zn/PANI batteries, Zn 2+ could serve as the cation species associated with the imine-related redox reaction, while the counter anions will participate in the reaction between the =NH + -a nd -NHmoieties during charge/discharge processes.A lthough they often deliver limited specific capacity (< 200 mAh g À1 )due to their low available doping level, they usually display more stable electrochemical performance in comparison with other most previous reported cathode materials.A saresult, they were usually utilized to act as the electrodes of flexible ZIBs with various configurations. [57][58][59][60][61][62] Thee lectrochemical performance of conductive polymers could be further improved by the optimization of electrolyte, [27,63] hybridization with inorganic materials, [28,[64][65][66][67] morphology regulation [68] and copolymerization. [38,[69][70][71] Forinstance,the conductive polymers could be intercalated into the interlayers of metal oxides to effectively eliminate the structural changes of them during discharge/charge processes,r esulting in excellent rate capability and long cycling life.…”

“…TheP ANI-GO/ CNTs composite could display ah igh specific capacity of 247 mAh g À1 at ac urrent density of 100 mA g À1 . [66] Such increased practical capacity depends on not only the high electronic conductivity supplied by interconnected CNTs network, but also the improvement of doping level by GO.In addition, the concentration of electrolytes plays an important role in their ionic conductivity.A td ifferent electrolyte concentrations,the specific capacities of Zn/organic batteries would be varied. [73]…”

Recent Progress on High‐Performance Cathode Materials for Zinc‐Ion Batteries

“…Similarly, Li and co‐workers discovered that graphene oxide (GO) with abundant oxygen groups can also serve as a local proton reservoir which can ease PANI protonation (Figure 10c). [ 116 ] The oxygen‐containing functional groups of GO release H + in aqueous electrolyte, which enables GO as an organic acid. The study showed that a larger portion of N in the PANI backbone is protonated as a result of the GO incorporation, which enables higher charge transfer capacity during cycling.…”

“…This would support the claim that co-intercalation of Zn 2þ and Na þ have occurred. Ex situ XRD shows shifts of both the (116) and (113) diffractions toward lower angles when the cell is discharged to 1.2 V, which is ascribed to Na þ intercalation (Figure 6c). When further discharged to 0.6 V, upshifts of the (211) and (113) diffractions can be observed and are attributed to Zn 2þ intercalation.…”

A Polymer/Graphene Composite Cathode with Active Carbonyls and Secondary Amine Moieties for High‐Performance Aqueous Zn‐Organic Batteries Involving Dual‐Ion Mechanism

“…[38][39][40][41][42] For example, in the case of Zn/polyaniline (PANI) batteries, the deposition/dissolution of Zn 2+ /Zn occurs in the anode side, while the counter anions will participate in the reaction between the NH +  and NH moieties in the cathode side during charge/discharge processes, which is regarded as dual-ion mechanism. [41,43,44] In spite of that, their limited capacity is still a considerable obstacle to their further development. Hence, if the active carbonyls and electrochemical active part in PANI can be combined into cathode to assemble AZIBs, enhanced energy density might be achieved for their large capacity and high voltage.…”