β-Hydrogen of Polythiophene Induced Aluminum Ion Storage for High-Performance Al-Polythiophene Batteries

Abstract

The urgent need for large-scale, low-cost energy storage has driven a new wave of research focusing on innovative batteries. Due to the high capacity and the low-cost of elemental Al, aluminum-ion batteries (AIBs) are expected as promising candidates for future energy storage. However, further development of AIBs is restricted by the performance of existing carbonbased cathodes and metal chalcogenide cathode materials. In this work, we deposited polythiophene (Pth) on a graphene oxide (Pth@GO) composite and used it as an AIB cathode material. This Pth@GO composite possesses high exposure of Pth active sites, high conductivity, and high structure stability while providing a very high discharge capacity (up to 130 mAh g −1 ) and outstanding cyclic stability (maintaining above 100 mAh g −1 after 4000 cycles). First principles calculations and experimental results show that the charge is stored on Pth@GO through an electrostatic attraction between AlCl 4 − and β-hydrogen (C β −H) sites in polythiophene.

Scalable Fabrication of LiMn2O4/Polythiophene with Improved Electrochemical Performance for Lithium-Ion Batteries

“…Detailed results and discussion are provided in the Supporting Information (S2). The results show that (1) aging LMO in ambient air for 4 months deteriorates the electrochemical performance, including the discharge specific capacity ( C dis ), cycling stability, rate capability, and coulombic efficiency (CE) at the first cycle (Figure S6); (2) PTh coating, especially for LMO/PTh-300, is capable of improving the aging resistance and electrochemical performance of LMO because the PTh coating not only protects LMO from direct contact with H 2 O/CO 2 in air and HF in the electrolyte but also resumes the conductive nature during the electrochemical tests. , Considering that 300 μL of thiophene relative to 10 g of LMO powders is sufficient for improving the electrochemical performance, we did not attempt to increase the amount of thiophene for LMO/PTh preparation. The weight percent of PTh in the composites is estimated to be lower than 3 wt %, assuming that all the added thiophene has been transformed into PTh.…”

Recent Progress on Organic Electrode Materials for Multivalent (Zn, Al, Mg, Ca) Secondary Batteries

“…Kong et al developed the Pth@GO composite electrode material, demonstrating a higher capacity than Pth and GO (Figure 9a). [59] Based on the storage mechanism of strong electrostatic interaction between charge carriers and the C β À H sites of the Pth chain, the Pth@GOÀ Al battery displays a high discharge capacity of 130 mAh g À 1 at 1 A g À 1 , with excellent rate performance and cycling stability (Figure9b).…”

Ultrafast and Long-Cycle Stable Aluminum Polyphenylene Batteries

“…The insertion/deinsertion of trivalent Al 3+ in the lattice of cathodes (MX n , X = O, S, Se) is really tough. − This is because the binding energy of trivalent Al 3+ to O 2– /S 2– is too strong compared to the monovalent Li + /Na + ion, resulting in rapid capacity decay and irreversibility and also causes a large voltage hysteresis between the charge–discharge curves and ultimately a lower energy efficiency. − While the intercalation reaction of [AlCl 2 ] + /[AlCl 4 ] − ion is more likely to occur and has a higher reversibility. Various types of graphite materials have been reported with capacities of 60–120 mA h/g and average discharge voltages of 1.5–2.0 V, and its capacity hardly decays after thousands of cycles. − However, artificial graphite and graphene materials often have an extremely high energy consumption during the synthesis process and display a poor rate performance in ultrahigh current density. − Organic conductive polymer materials, such as polyaniline and polythiophene, also undergo the [AlCl 2 ] + /[AlCl 4 ] − intercalation reaction and have high working voltages slightly lower than graphite materials and low cost and environmental friendliness. − However, these materials often fail to maintain long-term stability and suffer from a poor rate performance, mainly due to the inherent conductivity limit and irreversible dissolution in an acidic ionic liquid electrolyte. For this reason, there is an urgent need to find new cathode materials that are low in cost and can withstand high current charging and maintain ultralong cycle stability to promote the practical application.…”