| With the rapid development of society,increasing population and environmental problems,higher demands are placed on energy storage systems and technologies.Lithium-ion battery technology has been developed now very maturely in worldwide,but the reserves of lithium element in the earth’s crust are very low and the safety performance of lithium-ion batteries needs to be improved.In recent years,researchers have turned their attention to metal ion batteries,such as zinc and aluminum ion batteries,both of which are multivalent metal ion batteries that carry multiple charges and are expected to provide higher capacities.In addition,both elements are relatively high in the earth’s crust,so they are inexpensive and help develop large-scale energy storage systems.Aqueous zinc-based batteries（RZBs）and aqueous aluminum-based batteries（AABs）have great potential for application due to their green safety,low cost and high theoretical capacity.In the selection of their cathode materials,quinone organic compounds are widely used for their high theoretical capacity,reversible reactions and resource availability,however,small molecule quinone-based materials have problems in practical applications:they are less stable in electrolyte and easily dissolved in aqueous electrolyte.In this paper,chemical polymerization and physical combination of carbon materials are used to solve the problem and realize the application value of quinone-based organic compounds.The development of aqueous aluminum-based batteries is slowed by the effects of hydrogen precipitation and passivation when using metallic aluminum as anode.In this paper,we construct Zn-Al as a high-performance anode for aqueous aluminum-based batteries by interfacial modification of aluminum anode.Poly（2,3-dithio-1,4-benzoquinone）（PSBQ）was synthesized by chemical polymerization and characterized for its characteristic functional groups and structure to be used as a high-performance cathode for aqueous zinc-based batteries;PSBQ belongs to the carbonyl group,and the carbonyl group is used as an active site for electrochemical reactions with zinc ions,while its long polymer chain has a stable structure as an aqueous zinc-based battery cathode compared to small molecule quinones,which are easily dissolved in water.The PSBQ cathode showed a high discharge capacity of 217.7 m Ah g-1 with 85%capacity retention after 200 cycles at 1.0A g-1.The assembled bendable Zn||PSBQ cells maintained 90%capacity retention after 90°and 180°bending.The superior performance is attributed to the flexible molecular backbone generated by the polymerization reaction of PSBQ.It provides a new strategy for designing high-capacity polymer cathodes for aqueous Zn-based battery cathodes.Zn-Al was prepared by a simple one-step method to serve as the negative electrode of an aqueous aluminum-based battery.The zinc film deposited on the aluminum foil is closely attached to the aluminum foil and is structurally stable in the aqueous electrolyte of aluminum trifluoromethanesulfonate without peeling off.The overpotential of the assembled Zn-Al symmetric cell decreased from 2000 m V in the aluminum metal symmetric cell to about 40 m V,exhibiting a symmetric and smooth voltage plateau and stable cycling at 400 h.BQ@C was prepared as the cathode material for the aqueous aluminum-based battery by physical adsorption of p-benzoquinone on graded porous carbon;the initial discharge capacity of the battery was 440.5 m Ah g-1at 0.2 C and the capacity was maintained 66.8%after 110 cycles.This study provides some ideas and insights into the improvement of aluminum metal for more stable electrochemical performance in aqueous aluminum-based batteries,and can promote the development of aqueous aluminum-based batteries using aluminum metal as anode. |
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