Heterocyclic Conjugated Polymer Nanoarchitectonics with Synergistic Redox‐Active Sites for High‐Performance Aluminium Organic Batteries

Abstract

The development of cost-effective and long-life rechargeable aluminium ion batteries (AIBs) shows promising prospects for sustainable energy storage applications. Here, we report a heteroatom π-conjugated polymer featuring synergistic C=O and C=N active centres as a new cathode material in AIBs using a low-cost AlCl 3 /urea electrolyte. Density functional theory (DFT) calculations reveal the fused C=N sites in the polymer not only benefit good πconjugation but also enhance the redox reactivity of C=O sites, which enables the polymer to accommodate four AlCl 2 (urea) 2 + per repeating unit. By integrating the polymer with carbon nanotubes, the hybrid cathode exhibits a high discharge capacity and a long cycle life (295 mAh g À 1 at 0.1 A g À 1 and 85 mAh g À 1 at 1 A g À 1 over 4000 cycles). The achieved specific energy density of 413 Wh kg À 1 outperforms most Al-organic batteries reported to date. The synergistic redox-active sites strategy sheds light on the rational design of organic electrode materials.

Ultrafast and Long-Cycle Stable Aluminum Polyphenylene Batteries

“…This Al-PPP batteries also exhibit a stable cycling performance and high reversible capacities (78 and 73 mA h/g at 1.0 A/g) at high active material loadings of 4.0 and 8.0 mg/cm 2 (Figures e and S4). A typical overlapped charge–discharge curve shown in Figure f illustrate that this battery has a small voltage hysteresis and an energy efficiency of 84%, which is comparable to graphite and some recently reported organic cathodes and higher than other types of cathodes such as metal oxides, metal sulfides, and sulfur group element (Figure g). ,,− Figure S5 shows the self-discharge performance of the Al-PPP battery. The resting time increases from 2 to 6, 12, 24, and 48 h, and the discharge capacities are slight attenuated and maintained at 90, 86, 82, 78, and 74 mA h/g, respectively.…”

Promise and reality of organic electrodes from materials design and charge storage perspective

“…174 An exciting development over the past few years has been the rise of a broad class of organic materials for high-performance Al-organic batteries. [175][176][177][178] Notably, quinones are remarkable for their increased specic capacity, enhanced redox potential and multielectron reactivity. Apart from the para-and/or orthoquinone, the electronic integration of the contiguous carbonyl groups leads to the creation of negative enolates, which can be conjugated with Al ions to maintain the structure.…”

Enhanced cycling stability and rate capability of a graphene-supported commercialized Vat Blue 4 anode for advanced Li-ion batteries

“…Li + reaction with C=C and C=O to form C-C-Li and C-O-Li, respectively 49. Then, during the charging process, the tendency of enhanced peaks of C=C and C=O can be observed,indicating the removal of Li + from C-C-Li and C-O-Li.…”