Zinc-Ion Storage Mechanism of Polyaniline for Rechargeable Aqueous Zinc-Ion Batteries

Abstract

Aqueous multivalent ion batteries, especially aqueous zinc-ion batteries (ZIBs), have promising energy storage application due to their unique merits of safety, high ionic conductivity, and high gravimetric energy density. To improve their electrochemical performance, polyaniline (PANI) is often chosen to suppress cathode dissolution. Herein, this work focuses on the zinc ion storage behavior of a PANI cathode. The energy storage mechanism of PANI is associated with four types of protonated/non-protonated amine or imine. The PANI cathode achieves a high capacity of 74 mAh g−1 at 0.3 A g−1 and maintains 48.4% of its initial discharge capacity after 1000 cycles. It also demonstrates an ultrahigh diffusion coefficient of 6.25 × 10−9~7.82 × 10−8 cm−2 s−1 during discharging and 7.69 × 10−10~1.81 × 10−7 cm−2 s−1 during charging processes, which is one or two orders of magnitude higher than other reported studies. This work sheds a light on developing PANI-composited cathodes in rechargeable aqueous ZIBs energy storage devices.

The Synthesis of Manganese Hydroxide Nanowire Arrays for a High-Performance Zinc-Ion Battery

“…As shown in Figure 5 f, the diffusion coefficients of Mn(OH) 2 nanowire arrays are 4.5 × 10 −8 ~1.0 × 10 −9 cm 2 s −1 and 1.0 × 10 −9 ~2.7 × 10 −11 cm 2 s −1 for charging and discharging processes, respectively, reflecting the rapid ionic diffusion kinetics. Compared with other referenced cathode materials ( Table S1 ), the diffusion coefficients of Mn(OH) 2 nanowire arrays were higher than the Zn 2+ ion diffusion coefficient in MnO 2 [ 16 , 17 , 18 , 19 , 47 , 48 ], V 2 O 5 [ 20 , 21 , 49 , 50 , 51 ] and that in other related materials [ 24 , 25 , 52 ]. The high Zn 2+ ion diffusion coefficients also benefited from the specific configuration in which the vertically aligned arrangement was beneficial to electron transport and the free space between the nanowires, which can provide more ion-diffusion pathways.…”

“…The rate performance of the product is shown in Figure 4 c. Mn(OH) 2 delivered excellent reversible rate capacities of 146.3, 128.5, 114.2, 101.4, 94.5 and 88.2 Ma h g −1 at the current densities of 0.1, 0.2, 0.3, 0.5, 0.7 and 1.0 Ag −1 , respectively. The value is comparable to an MnO 2 nanofiber [ 29 ], Mn(OH) 2 @ porous Ni [ 38 ], V 2 O 5 /CNT [ 21 ] and PANi [ 25 ]. More importantly, when the rate returns to 0.1 Ag −1 , the specific capacity of the sample retains 94.8% of the initial capacity, indicating good layer structure stability and excellent electrochemical reversibility.…”

“…To improve the intrinsic safety of ZIBs, some scientists are devoted to suppressing the growth of zinc dendrites [ 9 , 10 , 11 ]. Current research efforts are mainly focused on exploring high-performance cathode materials of ZIBs, such as manganese-based [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ] and vanadium-based materials [ 20 , 21 ], and so on [ 22 , 23 , 24 , 25 ]. Manganese-based oxides are the most favorable cathode materials for aqueous ZIBs because of these advantages.…”

Tough Hydrogel Electrolytes for Anti‐Freezing Zinc‐Ion Batteries

“…As shown in Figure 3G-I, at 2 A g −1 , the battery provided a reversible capacity of 52.2 and 57.5 mA h g −1 after 1000 cycles at 25 °C and 30 000 cycles at −20 °C, respectively, with an imperceptible decrease in capacity at −20 °C, showing its ultrahigh stability. The decrease in capacity at 25 °C (Figure 3G) may be attributed to the deprotonation and swelling/shrinking of PANi, [85][86][87] which might be alleviated at low temperatures, leading to higher stability. When tested at −30 °C, the battery displayed a reversible capacity of 57.5 mA h g −1 after 1000 cycles at 0.5 A g −1 , with a small 5% capacity fading compared to the 10th cycle.…”

Engineering Oxygen Vacancies on VO2 Multilayered Structures for Efficient Zn2+ Storage

“…[1][2][3][4] Zinc-ion batteries (ZIBs) are considered as a promising alternative of LIBs thanks to the low redox potential (À 0.76 V vs. standard hydrogen electrode) and high theoretical capacity (820 mAh g À 1 ) of zinc and the safety inherent of aqueous electrolyte. [5][6][7] At present, manganese-based compounds, [8][9][10] vanadium-based materials, [11,12] Prussian blue analogues [13] and organic species [14][15][16] have been explored as ZIB cathode materials. Among them, manganese-based compounds often suffer from severe capacity decay due to Mn 2 + dissolution while Prussian blue analogs usually have a relatively low capacity.…”