Jianghe Liu,Sultan Ahmed,Zeba Khanam,Ting Wang,Shenhua Song
In this study, novel ionic liquid-incorporated Zn-ion conducting polymer electrolyte membranes containing polymer matrix poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), along with zinc trifluoromethanesulfonate Zn(Tf)2, are prepared and investigated. It is ascertained that the optimal membrane ILPE-Zn-4 (the mass ratio of EMITf:Zn(Tf)2:PVDF-HFP is 0.4:0.4:1), with abundant nanopores, exhibits a high amorphousness. At room temperature, the optimized electrolyte membrane offers a good value of ionic conductivity (~1.44 × 10−4S cm−1), with a wide electrochemical stability window (~4.14 V). Moreover, the electrolyte membrane can sustain a high thermal decomposition temperature (~305 °C), and thus its mechanical performance is sufficient for practical applications. Accordingly, the ionic liquid-incorporated Zn-ion conducting polymer electrolyte could be a potential candidate for Zn-based energy storage applications.Keywords:polymer electrolyte;Zn-ion conducting;ionic liquid;ionic conductivity
The issues of Zn dendrite and severe Zn 2+ transport destabilization in the electrode/electrolyte interface have been the main obstacles to the commercialization of aqueous Zn-based batteries. Here, a disordered zinc silicate (ZSO) artificial solid electrolyte interphase with high Zn 2+ conductivity (9.29 mS·cm −1 ) is proposed to address these dilemmas. The disordered ZSO interphase possesses sufficient tunnels for fast Zn 2+ transport and highly reversible Zn plating/stripping, which can redistribute the Zn 2+ flux and guide uniform Zn deposition to achieve a dendrite-free Zn metal anode. As a proof of concept in zinc-ion batteries, the Zn@ZSO//NH 4 V 4 O 10 battery delivers a capacity of 336.8 mAh·g −1 at 0.2 A·g −1 , with a capacity retention of 90.1% at 5 A·g −1 over 1,000 cycles. As for the Zn@ZSO//I 2 battery, by inhibiting I 3 − diffusion, 97.98% of capacity is retained after shelving for 60 h. This work provides enlightenment into interface designing and iodide diffusion suppression to accelerate the commercialization of high-performance zinc-based batteries.
Solid-state polymer electrolytes (SPEs) are promising for high-performance zinc metal batteries (ZMBs), but they encounter critical challenges of low ionic conductivity, limited Zn2+ transference number (tZn2+), and an unstable electrolyte-electrode interface. Here, we present an effective approach involving a missing-linker metallic organic framework (MOF)-catalyzed poly(ethylene glycol) diacrylate (PEGDA)/polyacrylamide (PAM) copolymer SPE for single Zn2+ conduction and seamless electrolyte-electrode contact. The single-Zn2+ conduction is facilitated by the anchoring of the OTF– anions onto the unsaturated metal sites of missing-linker MOF, while the PEGDA and PAM chains in competitive coordination with Zn2+ ions promote rapid Zn ion transport. Our all-solid-state electrolyte simultaneously achieves a superior ionic conductivity of 1.52 mS cm–1 and a high tZn2+ of 0.83 at room temperature, alongside uniform Zn metal deposition (1000 cycles in symmetric cells) and high Zn plating/striping efficiencies (>99% after 600 cycles in asymmetric cells). Applications of our SPE in Zn//VO2 full cells are further demonstrated with a long lifespan of 2000 cycles and an extremely low-capacity degradation rate of 0.012% per cycle. This work provides an effective strategy for using a missing-linker MOF to catalyze competitively coordinating copolymers for accelerating Zn2+ ion conduction, assisting the future design of all-solid-state ZMBs.