耦合无枝晶锌负极和可逆脱嵌钙离子的磷酸钒钠正极实现先进钙锌混合离子电池

An advanced Ca/Zn hybrid battery enabled by the dendrite-free zinc anode and a reversible calcification/decalcification NASICON cathode

混合离子电池综合了单一离子电池的优点,为开发高性能二次电池提供了新的见解.本文合成了一种有无定形活性碳和还原氧化石墨烯包覆的NASICON型正极材料(NVP@AC@rGO)用于钙离子的可逆脱嵌,并组装了一种与锌金属负极和水系混合电解质耦合的Ca/Zn离子混合电池.这种完美的结合不仅充分发挥了钙离子在NASICON结构中优异的扩散动力学,而且巧妙利用钙离子的低还原电位,形成静电屏蔽效应,从而抑制了锌枝晶的形成.因此,该混合电池具有超高的比容量,出色的倍率性能以及循环稳定性.这种巧妙的组合平衡了单一多价离子电池的优缺点,为设计高性能的水性多价离子电池提供了一种新的可行途径.

The proposal of hybrid ion batteries,which can integrate the advantages of the single ion battery,opens up a new route for developing high-performance secondary batteries.Herein,we successfully constructed an aqueous hybrid battery comprised of polyanionic-type cathode material(Na_(3)V_(2)(PO_(4))_(3),NVP),Zn metal anode,and aqueous Ca^(2+)/Zn^(2+)hybrid electrolyte.This exciting combination gives full play to not only the excellent diffusion dynamics of Ca^(2+)in the NASICON(sodium super ion conductors)structure but also the electrostatic shielding effect of Ca^(2+)with low reduction potential that inhibits the formation of zinc dendrites.As results,the NVP//Zn Zn/Ca hybrid battery delivers favorable specific capacity with outstanding rate performance(85.3 mAh g^(-1)capacity at 1 C,60.5 mAh g^(-1)capacity at 20 C),and excellent cycle stability(74%capacity retention after 1300 cycles).