【摘要】 水系锌碘电池（AZIBs）是一种非常受欢迎的绿色储能技术,但它的能量密度极大地限制了其应用.在此,我们报道了一种高能量密度的可充电AZIBs,通过将高质量碘锚定到具有大微孔体积和富吡啶氮掺杂的独特分级多孔碳中来实现.多孔碳结合了微孔对碘的强约束和氮掺杂对碘的强化学吸附的优点,可使碘的负载量高达61.6 wt%.密度泛函理论计算和实验研究表明,氮掺杂所赋予的丰富活性位点能促进AZIBs的氧化还原动力学,吡啶氮掺杂对AZIBs的吸附可逆转化比普通氮掺杂更有效.高负载碘电极在1.0 C时表现出219.3 mA h g^-1的高容量,优异的速率性能,以及优越的循环稳定性,在5.0 C时,循环10,000次内的容量衰减极低,每圈仅为0.00147%.由三节电池串联的初步装置,能量密度高,按电池总质量计算可达72.6 W h kg^-1,几乎是商用铅酸和镍-镉电池能量密度的两倍.该水系电池的高能量密度和长循环寿命使其在大规模储能应用领域具有巨大潜力.更多还原

【Abstract】 Aqueous Zn-I₂ batteries（AZIBs） are highly desirable for green energy-storage technologies, but their development was greatly limited by their unsatisfactory energy densities. Herein, we report high-energy-density rechargeable AZIBs achieved by anchoring high-mass iodine to a distinctive N-doped hierarchical porous carbon（NHPC） material with large micropore volume and rich N-doping. The NHPC combined strong iodine confinement caused by the micropore and powerful chemisorption of iodine species with pyridine-N doping, which enabled high loads of iodine up to 61.6 wt%.Notably, density functional theory calculations and experimental studies showed that abundant pyridine-N active sites promoted electron transfer, and the interconnected micromesoporous structure facilitated the Zn-ion diffusion to synergistically promote the redox kinetics of AZIBs. The high content of iodine-loading cathode exhibited a high capacity of 219.3 mA h g^-1at 1.0 C, indicating excellent rate capability and superior cycling stability with a low capacity decay of 0.00147% per cycle within 10,000 cycles at 5.0 C. In addition, a preliminary device assembled with three batteries in series provided a high energy density of up to 72.6 W h kg^-1calculated by the total mass of the battery, which is almost two times that of the commercial aqueous lead-acid and Ni-Cd batteries. The high energy density and long cycle life of this aqueous battery indicate its great application potential in large-scale energy storage.更多还原