Quasi-Solid-State Flexible Zn–Air Batteries with a Hydrophilic-Treated Co@NCNTs Array Electrocatalyst and PEO–PANa Electrolyte
Minghui Lv, Chan Luo, Jiale Li, Yulin Zhang, Qin Zeng, Niu Huang, Shenggao Wang, Yong Zheng, Wei Liu, Liqun Ye
Abstract
In this work, we report an efficient and stable electrocatalyst (MoS 2 –Co@NCNTs) with a dense layer of MoS 2 nanosheets compounded on the surface of Co@NCNTs. When tested in an oxygen-saturated electrolyte, MoS 2 –Co@NCNTs undergoes electrochemical reconfiguration (MoS 2 –Co@NCNTs–ER) and the MoS 2 nanosheets are oxidized, resulting in some high-valence molybdenum–oxygen compounds (MoO x ). The oxidized MoS 2 –ER nanoparticles significantly enhanced the hydrophilicity of the Co@NCNTs. Hydrophilicity improvement increased the electrochemical active surface area (ECSA) of MoS 2 –Co@NCNTs–ER and promoted the ion transport between the catalyst and electrolyte, which led to the enhanced OER/ORR catalytic performance compared with Co@NCNTs. Meanwhile, a PEO–PANa GPE with high electrical conductivity and excellent electrolyte absorption and retention capacity was reported. QSS-F-ZABs assembled with MoS 2 –Co@NCNTs and PEO–PANa GPE exhibit enhanced charge/discharge performance and long-cycle stability with a stable cycle of 200 h at a current density of 2 mA cm –2 and 160 h at a current density of 5 mA cm –2 .