Monolithic Phosphate Interphase for Highly Reversible and Stable Zn Metal Anode

Zinc metal battery (ZMB) is promising as the next generation of energy storage system, but challenges relating to dendrites and corrosion of the zinc anode are restricting its practical application. Here, to stabilize Zn anode, we report a controlled electrolytic method for a monolithic solid-electrolyte interphase (SEI) via a high dipole moment solvent dimethyl methylphosphonate (DMMP). The DMMP-based electrolytes can generate a homogeneous and robust phosphate SEI (Zn-3(PO4)(2) and ZnP2O6). Benefiting from the protecting impact of this in situ monolithic SEI, the zinc electrode exhibits long-term cycling of 4700 h and a high Coulombic efficiency 99.89 % in Zn|Zn and Zn|Cu cell, respectively. The full V2O5|Zn battery with DMMP-H2O hybrid electrolyte exhibits a high capacity retention of 82.2 % following 4000 cycles under 5 A g(-1). The first success in constructing the monolithic phosphate SEI will open a new avenue in electrolyte design for highly reversible and stable Zn metal anodes.

Automated summary

To stabilize the zinc anode in zinc metal batteries, researchers have developed a controlled electrolytic method using a high dipole moment solvent dimethyl methylphosphonate (DMMP) to create a monolithic solid electrolyte interphase (SEI). This DMMP-based electrolyte generates a homogeneous and robust phosphate SEI (Zn-3(PO4)(2) and ZnP2O6). With the protection provided by this in situ monolithic SEI, the zinc electrode exhibits long-term cycling performance and high Coulombic efficiency in both zinc|zinc and zinc|copper cells. The use of a DMMP-H2O hybrid electrolyte in a full V2O5|zinc battery also results in high capacity retention following a large number of cycles.