A new phosphate member: ZnMn2(PO4)2 as an advanced cathode material for aqueous and nonaqueous zinc ion batteries

Exploring an appropriate and economical efficient cathode material for zinc ion batteries plays an important role in overcoming current existing challenges and realizing final practical application. A novelty explored phosphate ZnMn2(PO4)(2) coated by a thin carbon layer [ZnMn2(PO4)(2) @C] was synthesized and employed as cathode material for both aqueous and nonaqueous zinc storage system, featuring with a tunnel structure and working as a host for the Zn2+ extraction and insertion. It shows a reversible specific capacity of 67 mA h g(-1) in 1 M Zn(CF3SO3)(2) aqueous system. When coupling with FePO4, the full batteries containing ZnMn2(PO4)(2) @C presented a capacity of 174 mA h g(-1) with a high voltage plateaus of 1.17 V vs. Zn/Zn2+ in Zn(TFSI)2 nonaqueous electrolyte. The Zn2+ diffusion behavior for ZnMn2(PO4)(2) contributes the main electrochemical process and the diffusion coefficient is in a scope of 10-11-10-14 cm(2) s(-1) for aqueous system and 10(-12)-10(-14) cm2 s(-1) for nonaqueous system, respectively. Combined with the high thermal stability, the low ion apparent activation energy and high diffusion coefficient can guarantee the superior electrochemical performance. A new phosphate family member for next-generation aqueous and non aqueous zinc ion batteries was explored. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

A novel phosphate ZnMn2(PO4)(2) coated by a thin carbon layer [ZnMn2(PO4)(2) @C] was synthesized and employed as cathode material for zinc ion batteries, showing excellent electrochemical performance with reversible specific capacity of 67 mA h g(-1) in aqueous system and 174 mA h g(-1) in nonaqueous system.