A novel quinone-based polymer electrode for high performance lithium-ion batteries

Abstract

dissolution issue without sacrificing the electrochemical performance.In the past two decades, several strategies have been comprehensively proposed and evaluated. For example, one of the earliest attempts was through the synthesis of lithium salts [8,9,[13][14][15], which delivered relatively better cycling stability and specific capacity compared with the previously reported small molecules. It was reported that Li 2 C 8 H 4 O 4 (Li terephthalate) could accept two lithium ions to give an initial reversible capacity of 300 mAh g −1 at 1 C [9]. In addition, all-organic LIBs fabricated by the tetralithium salt of 2,3,5,6-tetrahydroxy-1,4-benzoquinone (Li 4 C 6 O 6 , THQ) and the tetralithium salt of 2,5-dihydroxyterephthalic acid (Li 4 C 8 H 2 O 6 , Li 4 DHTPA) were evaluated respectively [8,14]. The cells were able to provide reversible capacities of 120 and 200 mAh g −1 after 50 cycles and 20 cycles, separately at low current densities. Although these organic salts displayed better electrochemical performances as compared with the old-designed organic molecules, the cycling ability of them was still not stable and the specific capacities were still low as compared with the inorganic electrode materials. From the perspective of molecular design, another strategy is to increase the molecular weight of organic compounds by polymerization [16]. Especially, these polymers with large conjugated structures are not easily dissolved into the electrolytes. Nevertheless, increasing the molecular weight through polymerization could only somewhat resolve the dissolution issue. More importantly, the specific capacity of the larger structures will decrease accordingly.Hence, in order to achieve a compromising result between the cycling stability and the specific capacity, our strategy is to develop quinone-based rigid backbone polymers with the chemically stable thianthrene structures. Recently, polymers containing redox-active carbonyl groups (C=O) have been thoroughly investigated [12,[17][18][19][20][21][22][23][24][25][26][27]. Especially, quinones are regarded as the most promising types ABSTRACT Designing of high electrochemical performance organic electrode materials has attracted tremendous attention. Recent investigations revealed that quinone-based polymers along with the stable thioether bonds could achieve a high specific capacity and a good cycling stability simultaneously. In this study, we synthesized a novel ladder-structured polymer poly(2,3-dithiino-1,4-benzoquinone) (PDB) through a simple two-step polymerization. The electrochemical performance indicated that PDB could achieve a high reversible specific capacity of 681 mAh g −1 with 98.4% capacity retention after 100 cycles. A good rate performance was also achieved with a fast recovery of the capacity after testing at different current densities. Ultra-long cycling performance of PDB was also investigated. The promising results of PDB provided us more confidence to continue searching for high performance polymers through the modification of organic structu...

Novel Conjugated Ladder-Structured Oligomer Anode with High Lithium Storage and Long Cycling Capability

“…As far as we know, this capacity performance of PPCQ is better than that of most reported organic anodes, including lithium salts 8, 15 and carbonyl compounds. 42,43 It is worthy to note that such a good result is comparable to or even better than the metal-based inorganic anodes that reported with high 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 capacity performances so far, for examples, SnO 2 (580 mAh g -1 after 100 cycles), 44 α-Fe 2 O 3 (945 mAh g -1 after 30 cycles) 45 and Co 3 O 4 (970 mAh g -1 after 30 cycles). 46 According to the theoretical capacity calculation, 3 if we consider that one lithium ion per formula unit of PPCQ contributes to 129 mAh g -1 , the reversible capacity of 1678 mAh g -1 , referring to a utilization of 93.1% of its theoretical capacity (~1802 mAh g -1 ), indicates that PPCQ is capable of accepting nearly thirteen lithium ions.…”

Molecular Engineering with Organic Carbonyl Electrode Materials for Advanced Stationary and Redox Flow Rechargeable Batteries

“…In addition, the easily dissolved carbonyls (raw materials or radical products) are shuttled to the Li anode with side reactions, resulting in low Coulombic efficiency and poor cycling stability. One is by increasing the molecular weight through polymerization (Figure 8), [119][120][121][122][123][124][125][126][127] and the other is by enhancing the polarity through salt formation (Figure 9). Therefore, most research interests so far have focused on solving this problem and enhancing the stability of carbonyls and extending cycling life.…”

Polymer Electrode Materials for High‐Performance Lithium/Sodium‐Ion Batteries: A Review

“…Similar to the PTCDA structure with active carbonyl groups and the stable backbone, another organic material that has attracted the interest of researchers is PDB and poly(2,5‐dihydroxyl‐1,4‐benzoquinonyl sulfide) (PDBS). Xie et al synthesized ladder‐structured polymer PDB, showing good rate performance and faster recovery of the capacity after testing at different current densities . Liu et al synthesized PDBS and applied it as the cathode material for LIBs .…”