The Progress and Prospect of Tunable Organic Molecules for Organic Lithium-Ion Batteries

Abstract

Compared to inorganic electrodes, organic materials are regarded as promising electrodes for lithium-ion batteries (LIBs) due to the attractive advantages of light elements, molecular-level structural design, fast electron/ion transferring, favorable environmental impacts, and flexible feature, etc. Not only specific capacities but also working potentials of organic electrodes are reasonably tuned by polymerization, electron-donating/withdrawing groups, and multifunctional groups as well as conductive additives, which have attracted intensive attention. However, organic LIBs (OLIBs) are also facing challenges on capacity loss, side reactions, electrode dissolution, low electronic conductivity, and short cycle life, etc. Many strategies have been applied to tackle those challenges, and many inspiring results have been achieved in the last few decades. In this review, we have introduced the basic concepts of LIBs and OLIBs, followed by the typical cathode and anode materials with various physicochemical properties, redox reaction mechanisms, and evolutions of functional groups. Typical charge−discharge behaviors and molecular structures of organic electrodes are displayed. Moreover, effective strategies on addressing problems of organic electrodes are summarized to give some guidance on the synthesis of optimized organic electrodes for practical applications of OLIBs.

Immobilizing Redox‐Active Tricycloquinazoline into a 2D Conductive Metal–Organic Framework for Lithium Storage

“…We thus hypothesize that there are nine‐electron related redox‐active behavior of TQ for Li + storage. With nine Li + ions loaded, the calculated theoretical specific capacity of TQ can reach 752.9 mAh g −1 , which is among one of the highest capacities in organic electrode materials [3b,d] . The excellent redox activity and high C 3 symmetry make TQ to be potential organic building block of robust frameworks for electrochemical applications.…”

Practical Quinone-Based Organic Supercapacitor > 6 V

“…2,4,5 However, the inorganic batteries currently in use are expensive because they use rare metals that are limited resources and are unevenly distributed, sometimes available only in con ict zones. 6,7 In addition, inorganic materials are often synthesized under harsh conditions, such as high temperature and pressure, which consumes a large amount of energy. 7,8 To make matters worse, the use of toxic metals, such as cobalt, induces severe environmental pollution.…”

“…9,[11][12][13] Secondly, organic compounds are often synthesized under mild conditions from renewable resources, which does not require tons of energy for mass production as inorganic materials do. 7,9,10,[13][14][15] Thirdly, it is easy to tune the theoretical capacity and redox potential by modifying the molecular structure. 9,13,16 Carbonyl compounds, especially quinones, have two redox centers in a single molecule, leading to a high capacity of up to 496 mAh g -1 .…”

“…6,7 In addition, inorganic materials are often synthesized under harsh conditions, such as high temperature and pressure, which consumes a large amount of energy. 7,8 To make matters worse, the use of toxic metals, such as cobalt, induces severe environmental pollution. 7,9,10 Therefore, it would be a better choice to avoid using such inorganic batteries for smart grids.…”

“…7,8 To make matters worse, the use of toxic metals, such as cobalt, induces severe environmental pollution. 7,9,10 Therefore, it would be a better choice to avoid using such inorganic batteries for smart grids.…”