Investigation of ion-electrode interactions of linear polyimides and alkali metal ions for next generation alternative-ion batteries

Abstract

Organic electrode materials offer unique opportunities to utilize ion-electrode interactions to develop diverse, versatile, and high-performing secondary batteries, particularly for applications requiring high power densities. However, a lack of well-defined...

Unexpected Direct Synthesis of Tunable Redox-Active Benzil-Linked Polymers via the Benzoin Reaction

“…Decreasing the charge density (i.e., increasing the size) of the monovalent cation from Li + to n Bu 4 N + resulted in a decrease in the magnitude of the second reduction potential, from 2.031 V (Li + ) to 1.899 V (Na + ) to 1.740 V (K + ) and 1.773 V ( n Bu 4 N + ) vs Li/Li + , respectively (SI Table S13, see Section S12 for further discussion on n Bu 4 N + ). This finding suggests that among monovalent cations, Li + best stabilizes the doubly reduced form of poly­(BTDA)-EG due to the hard–hard match of the reduced carbonyl units and the Li + cations. ,− …”

“…One of the most exciting features of organic electrode materials is that they can be readily adapted to work with almost any cation, including those such as Na + and Mg 2+ that are more abundant than Li + , − and their redox properties can be optimized by tuning hard–soft acid–base interactions. − Indeed, previous molecular studies have demonstrated that 1,2-diones are promising potential electrode materials for Mg-ion batteries because the two one-electron waves observed with monovalent cations such as Li + collapse into a single two-electron reduction wave with Mg 2+ cations due to the excellent hard–hard match of the divalent cation and the reduced carbonyl groups . However, this promising feature has not been demonstrated in polymeric electrode materials to date.…”

Unexpected Direct Synthesis of Tunable Redox-Active Benzil-Linked Polymers via the Benzoin Reaction

“…This finding suggests that among monovalent cations, Li + best stabilizes the doubly reduced form of poly(BTDA)-EG due to the hard-hard match of the reduced carbonyl units and the Li + cations. 29,[68][69][70] Intriguingly, switching from monovalent cations to divalent Mg 2+ caused the second reduction peak to dramatically shift to 2.501 V vs. Li/Li + , leading the second reduction peak to almost merge with the first peak to reveal a nearly simultaneous twoelectron transfer (Figure 8c). This finding suggests that Mg 2+ best stabilizes doubly reduced poly(BTDA)-EG.…”

“…One of the most exciting features of organic electrode materials is that they can be readily adapted to work with almost any cation, including those such as Na + and Mg 2+ that are more abundant than Li + , [65][66][67] and their redox properties can be optimized by tuning hard-soft acid-base interactions. [68][69][70] Indeed, previous molecular studies have demonstrated that 1,2-diones are promising potential electrode materials for Mg-ion batteries, because the two one-electron waves observed with monovalent cations such as Li + collapse into a single two-electron reduction wave with Mg 2+ cations due to the excellent hard-hard match of the divalent cation and the reduced carbonyl groups. 29 However, this promising feature has not been demonstrated in polymeric electrode materials to date.…”

From amorphous to crystalline: a universal strategy for structure regulation of high-entropy transition metal oxides

“…Lithium-ion batteries (LIBs) have been widely used in the elds of new-energy electric vehicles, portable electronic devices, and short to mid-term stationary energy storage, occupying a great share in the highly competitive battery market. [1][2][3][4] A conventional lithium-ion battery typically consists of a modied carbon-based anode and a lithium transition metal oxide-based cathode. [5][6][7] In the face of rapid developments in science and technology, these traditional LIB electrode materials are increasingly unable to meet the demanding requirements for capacity, energy density, safety, size and cost.…”