Electrophoresis-deposited polyacrylic acid/Ti3C2Tx MXene hybrid artificial layers for dendrite-free zinc anodes

Hybrid layers composed of polyacrylic acid and Ti3C2Tx MXene are coated on the surface of Zn foils via electrophoresis deposition processes, realizing the construction of an artificial protective coating with the pre-introduction of excess Zn2+ towards suppressing Zn2+ 2D diffusion of Zn deposition behavior. In this case, the abundant carboxyl groups of polyacrylic acid benefit to the fast transport of Zn2+ in addition to the shield of anions and oxidants, restraining the corrosion and passivation of Zn metal anodes. Moreover, the appearance of Ti3C2Tx MXene with two-dimensional arrangements strengthens the structure stability and improves the hydrophilicity of hybrid layers so as to restrict the dendrite growth of Zn metal anodes. Accordingly, polyacrylic acid/Ti3C2Tx MXene hybrid layer coated Zn electrodes in symmetric cells achieve a lifespan of over 1000 h at a current density of 3 mA cm−2 and an areal capacity of 3 mAh cm−2, superior to pristine Zn electrodes (107 h) and polyacrylic acid layer coated Zn electrodes (401 h). The full cell based on polyacrylic acid/Ti3C2Tx MXene hybrid layer coated Zn anodes and Na0.33V2O5 cathodes also exhibits a high capacity retention of 98.6 % after 1000 cycles at a current density of 5 A g−1.