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Abstract Developing low‐voltage carboxylate anode materials is critical for achieving low‐cost, high‐performance, and sustainable Na‐ion batteries (NIBs). However, the structure design rationale and structure‐performance correlation for organic carboxylates in NIBs remains elusive. Herein, the spatial effect on the performance of carboxylate anode materials is studied by introducing heteroatoms in the conjugation structure and manipulating the positions of carboxylate groups in the aromatic rings. Planar and twisted organic carboxylates are designed and synthesized to gain insight into the impact of geometric structures to the electrochemical performance of carboxylate anodes in NIBs. Among the carboxylates, disodium 2,2’‐bipyridine‐5,5’‐dicarboxylate (2255‐Na) with a planar structure outperforms the others in terms of highest specific capacity (210 mAh g−1), longest cycle life (2000 cycles), and best rate capability (up to 5 A g−1). The cyclic stability and redox mechanism of 2255‐Na in NIBs are exploited by various characterization techniques. Moreover, high‐temperature (up to 100 °C) and all‐organic batteries based on a 2255‐Na anode, a polyaniline (PANI) cathode, and an ether‐based electrolyte are achieved and exhibited exceptional electrochemical performance. Therefore, this work demonstrates that designing organic carboxylates with extended planar conjugation structures is an effective strategy to achieve high‐performance and sustainable NIBs.
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Three‐dimensional Polymers as Organic Cathodes for Affordable and Sustainable Sodium/Potassium‐ion Batteries
Abstract Redox‐active polymers (RAPs) are promising organic electrode materials for affordable and sustainable batteries due to their flexible chemical structures and negligible solubility in the electrolyte. Developing high‐dimensional RAPs with porous structures and crosslinkers can further improve their stability and redox capability by reducing the solubility and enhancing reaction kinetics. This work reports two three‐dimensional (3D) RAPs as stable organic cathodes in Na‐ion batteries (NIBs) and K‐ion batteries (KIBs). Carbonyl functional groups are incorporated into the repeating units of the RAPs by the polycondensation of Tetrakis(4‐aminophenyl)methane and two different dianhydrides. The RAPs with interconnected 3D extended conjugation structures undergo multi‐electron redox reactions and exhibit high performance in both NIBs and KIBs in terms of long cycle life (up to 8000 cycles) and fast charging capability (up to 2 A g−1). The results demonstrate that developing 3D RAPs is an effective strategy to achieve high‐performance, affordable, and sustainable NIBs and KIBs.
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- Award ID(s):
- 2142003
- PAR ID:
- 10478522
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Batteries & Supercaps
- Volume:
- 7
- Issue:
- 2
- ISSN:
- 2566-6223
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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