d‐Orbital Induced Electronic Structure Reconfiguration toward Manipulating Electron Transfer Pathways of Metallo‐Porphyrin for Enhanced AlCl2+ Storage

• Published in: Advanced materials (Weinheim) Vol. 36; no. 45; pp. e2409904 - n/a
• Main Authors: Jiao, Shuqiang, Han, Xue, Bu, Xudong, Huang, Zheng, Li, Shijie, Wang, Wei, Wang, Mingyong, Liu, Yunpeng, Song, Wei‐Li
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.11.2024
• Subjects: aluminum ion battery; Cobalt; Electrodes; Electron transfer; Electronic structure; Energy levels; Graphite; high specific capacity; Metallography; metallo‐porphyrin compounds; organic positive electrode; Porphyrins; Reconfiguration; Redox reactions; Stability
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202409904

The positive electrodes of non‐aqueous aluminum ion batteries (AIBs) frequently encounter significant issues, for instance, low capacity in graphite (mechanism: anion de/intercalation and large electrode deformation induced) and poor stability in inorganic positive electrodes (mechanism: multi‐electron redox reaction and dissolution of active materials induced). Here, metallo‐porphyrin compounds (employed Fe2+, Co2+, Ni2+, Cu2+, and Zn2+ as the ion centers) are introduced to effectively enhance both the cycling stability and reversible capacity due to the formation of stable conjugated metal‐organic coordination and presence of axially coordinated active sites, respectively. With the regulation of electronic energy levels, the d‐orbitals in the redox reactions and electron transfer pathways can be rearranged. The 5,10,15,20‐tetraphenyl‐21H,23H‐porphine nickle(II) (NiTPP) presents the highest specific capacity (177.1 mAh g−1), with an increment of 32.1% and 77.1% in comparison with the capacities of H2TPP and graphite, respectively, which offers a new route for developing high‐capacity positive electrodes for stable AIBs. The metallo‐porphyrin compounds (employed Fe2+, Co2+, Ni2+, Cu2+, and Zn2+ as the ion centers) can be used to regulate the electronic energy levels and electron transfer pathways. Thus, the NiTPP presents the highest specific capacity (177.1 mAh g−1), with an increment of 8.3% and 73.9% in comparison with the capacities of FeTPP and ZnTPP, respectively.