Multielectron Redox Compounds for Organic Cathode Quasi-Solid State Lithium Battery

Abstract

Two multielectron redox organic compounds, hexaazatrinaphthylene (3Q) and hexaazatriphenylenehexacarbonitrile (6CN) were evaluated as high energy density cathode materials of quasi-solid cells. The cathode dissolution, which has been an issue for organic cathodes, was suppressed and the cell cyclability drastically improved. 6CN, which exhibited low capacity and cyclability in conventional liquid electrolyte, was measured to possess the specific capacity of ∼420 mAh/g. The energy density of the cathode body was ∼720 Wh/kg. It was also discovered that implementation of depth-of-discharge management further improved cyclability. This study is a demonstrative case that cathode compounds deemed unusable in liquid electrolyte may turn usable in solid-state lithium cells.

A rechargeable lithium/quinone battery using a commercial polymer electrolyte

“…Accordingly new strategies should be proposed to simultaneously inhibit dissolution and improve the insertion kinetics in neutral organic host structures. Along this line, the introduction of a gelified polyethylene oxide (PEO)-based membrane (concept of quasi-solid state lithium battery) has recently shown interesting performance upon cycling for few small redox-active molecules in Li half cells thanks to a partial inhibition of the dissolution phenomenon [6,7]. However, given the complexity of the proposed electrolyte formulation with its multiphase components (PEO-ionic liquid-silica mixture), the exact role of the gelified membrane is rather difficult to identify.…”

Synthesis and electrochemical investigation of novel phosphite based layered cathodes for Li-ion batteries

“…In addition, highly efficient energy storage systems such as LIBs are crucial for the much anticipated shi from fossil fuels to renewable energy sources such as solar and wind energy. In the process of nding novel and better cathode materials, unconventional electrode materials such as organic compounds, [26][27][28][29] Metal Organic Frameworks (MOFs), [30][31][32][33][34] etc., have also been explored recently. Emphasis on the development of novel and cheaper cathode materials is one of the crucial steps towards cost reduction as the cathode materials account for over 40% of the total cost of LIBs.…”

Nitrogen‐Linked Hexaazatrinaphthylene Polymer as Cathode Material in Lithium‐Ion Battery

“…as an organic cathode material (Scheme S1, see the Supporting Information) with very high theoretical capacity (418 mA h −1 g −1 ). However, common drawbacks of a small organic molecule as cathode material, such as poor cycling stability and high solubility in polar electrolytes, were also observed for HATN . To improve its stability over cycles, efforts such as optimization of the electrolytes or HATN structure and construction of HATN polymers have been reported.…”

“…Hexaazatrinaphthalene (HATN) was first studiedby Sugimoto et al as an organic cathode material (Scheme S1, see the Supporting Information) [16][17][18][19][20][21][22][23][24] with very high theoretical capacity (418 mA h À1 g À1 ). However,c ommond rawbacks of as mallo rganic molecule as cathode material, such as poor cycling stability and high solubility in polar electrolytes,w ere also observed for HATN.…”