Organic Anode Material Research Articles

Maleamic Acid as an Organic Anode Material in Lithium-Ion Batteries.

Low-molecular-weight carbonyl-containing compounds are considered beneficial energy storage materials in alkali metal-ion/alkaline earth metal-ion secondary batteries owing to the ease of their synthesis, low cost, rapid kinetics, and high theoretical energy density. This study aims to prepare a novel carbonyl compound containing a maleamic acid (MA) backbone as a material with carbon black to a new MA anode electrode for a lithium-ion battery. MA was subjected to attenuated total reflection-Fourier-transform infrared spectroscopy, and its morphology was assessed through scanning electron microscopy, followed by differential scanning calorimetry to determine its thermal stability. Thereafter, the electrochemical properties of MA were investigated in coin cells (2032-type) containing Li metal as a reference electrode. The MA anode electrode delivered a high reversible capacity of about 685 mAh g−1 in the first cycle and a higher rate capability than that of the pristine carbon black electrode. Energy bandgap analysis, electrochemical impedance, and X-ray photoelectron spectroscopy revealed that MA significantly reduces cell impedance by reforming its chemical structure into new nitrogen-based highly ionic diffusion compounds. This combination of a new MA anode electrode with MA and carbon black can increase the performance of the lithium-ion battery, and MA majorly outweighs transitional carbon black.

Highly stable magnesium-ion-based dual-ion batteries based on insoluble small-molecule organic anode material

Magnesium-ion batteries (MIBs) are promising candidates for large-scale energy storage applications owing to their high volumetric capacity, low cost, and no dendritic hazards. However, the development of the MIBs is restricted owing to the obstacles of incompatibility between Mg metal and conventional electrolytes as well as the lack of suitable cathode materials with fast ion reaction kinetics, which lead to low working voltage, poor rate performance and unsatisfied cycling stability. In this work, a magnesium-ion based dual-ion battery (Mg-DIB) is constructed, using 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) as organic anode, expanded graphite (EG) with high potential and fast anion diffusion kinetics as cathode, and ionic liquid as electrolyte. The PTCDI was demonstrated to go through threefold coordination mechanism and hydrogen bond formation during Mg-ion insertion, which shows good insolubility in organic electrolytes and good structural stability. As a result, the Mg-DIB was demonstrated to exhibit a reversible discharge capacity of 57.7 ​mAh g−1 at 2C in the voltage range of 1–4 ​V, and good cycling stability with capacity retention of 95.7% after 500 cycles at 5C, which present a new way to design high-performance MIBs and other energy storage devices.

Superior anodic lithium storage behavior of organic pigment 2,9-dimethylquinacridone

Organic anode materials are of great importance for the development of lithium ion batteries (LIBs) with less reliance on inorganic minerals. In this work, it is found that 2,9-dimethylquinacridone (2,9-DMQA), an organic pigment, can have excellent electrochemical performances when serving as the anode material in LIBs. 2,9-DMQA based LIB anode manifests a high specific capacity of 1150 mAh g−1 at 0.1 A g−1. Even at a high current density of 5.0 A g−1, the capacity of 2,9-DMQA can still be retained at ~385 mAh g−1, outperforming many recently reported LIB anodes. The results from experiments and calculation suggest that 2,9-DMQA can reversibly associate with ~22Li+, corresponding to a theoretical capacity of 1732 mAh g−1. Additionally, the full-cell with 2,9-DMQA as anode and LiCoO2 as cathode can deliver the energy and power density of 325.8 Wh kg−1 and 1137.1 W kg−1, respectively, which are better than most of recently reported full-cells, implying the intriguing potential of the 2,9-DMQA anode in organic LIBs.

Preparation of organic poly material as anode in aqueous aluminum-ion battery

Rechargeable aqueous aluminum ion batteries (RAAB) have gained increasing attentions for large scale energy storage system due to their high safety, nontoxicity and low cost. However, lack of capable anode materials extremely hinders their potential application. As we all know, the anodic material of aluminum ion battery was limited, we report poly (3,4,9,10-perylentetracarboxylic diimide) (PPTCDI) under the different synthesis conditions as organic anode material for aqueous RAAB. The aluminum ions intercalation/deintercalation storage mechanism is affected by the different electrolyte concentrations. Upon their high capacity and cycling stability, our work would highlight potential application of conjugated polymer organic electrode materials for aqueous aluminum ion batteries.

Sodium–tin metal–organic framework anode material with advanced lithium storage properties for lithium-ion batteries

Tin-based materials have a high theoretical capacity as a negative electrode material for lithium-ion batteries. However, the problem of volume expansion during lithium-ion insertion and extraction has severely limited its development. In this work, sodium–tin metal–organic framework (Na–Sn-MOF) compounds were successfully synthesized by simple reflux method. And we studied the reaction mechanism of the compound as anode materials for lithium-ion batteries. The special stable structure constructed by the 1,4-benzenedicarboxylic acid ligands and larger Na+ ions will limit volume expansion of the tin effectively during the process of lithium–delithium. Therefore, the sodium–tin metal–organic framework anode material exhibits a high lithium storage capacity of 523 mAh g−1 with good cycling stability and rate capability. In addition, the Coulombic efficiency of the anode material for lithium-ion batteries is closed to 100% when the lithium ions are constantly embedded and released. This work for solving the problem of volume expansion of tin-based materials is quiet meaningful.

Redox-active poly(6-(1H-pyrrol-1-yl)quinoxaline) as a novel organic anode material for aqueous hybrid flow batteries

To develop efficient electrochemical energy storage systems for large-scale use of renewable energy, a novel quinoxaline-bearing redox-active conjugated polymer (poly(6-(1H-pyrrol-1-yl)quinoxaline), PPyQX) has been synthesized via a facile bromine oxidation polymerization approach and employed as electro-active anode material for aqueous hybrid flow batteries. The PPyQX displays a quasi-reversible redox reaction at −0.79 V vs the standard hydrogen electrode (SHE) with good stability in aqueous alkaline electrolytes. An aqueous hybrid flow battery is fabricated using the PPyQX as the anode material and K4Fe(CN)6 as the catholyte, respectively, which displays an open circuit potential of 1.15 V at 50% state of charge (SOC) and a discharge capacity of 67.1 mAh g−1 at the current density of 1 A g−1. The maximum power density reaches 2.7 and 1.5 W g−1 at 100% and 50% SOC, respectively. After 1000 charge-discharge cycles, ca. 74.8% of initial discharge capacity is retained, projecting an average capacity retention rate of ~99.975% per cycle. The coulombic efficiency is near to 93.8% and the round-trip energy efficiency is kept around 80.5%.

C60(OH)12 and Its Nanocomposite for High-Performance Lithium Storage.

Organic carbon materials, such as graphene and nanotubes, with a high specific capacity show promise in improving the energy density for lithium ion batteries (LiBs). Here, we report on the synthesis and characterization of C60(OH)12 and the C60(OH)12/graphene oxide (GO) composite and demonstrate their use as anode materials in LiBs. We find that the C60(OH)12/GO composite forms due to the chemical reactions between the carboxyl and epoxy groups of GO and the hydroxyl of C60(OH)12 nanoparticles and that C60(OH)12 uniformly grows on the surface of GO nanosheets. Using a suite of spectroscopy probes, we unequivocally show the mixing between C60(OH)12 and GO at the molecular level, which leads to superior battery performances. This composite has a reversible capacity of 1596 mAh g-1 at 0.2 A g-1, higher than the capacities of C60(OH)12 and GO. This composite has a superior cycling stability and excellent rate performance, making it a promising organic anode material for high-performance LiBs.

Optimization of Synthesis Conditions of Indigotindisulfonate Lithium Based on Orthogonal Experimental Design Method

With the developing research on anode materials for lithium ion batteries, organic anode materials have gained increasing attention nowadays. Compared with inorganic anode materials, organic anode materials have numerous material options and extensive sources. Moreover, they consume low energy and can enter carbon cycles, which are environment friendly. indigotindisulfonate lithium is characterized with a unique redox reaction and can be used as an anode material. Indigotindisulfonate Lithium can be produced by using indigo as a raw material sulfonated with fuming sulfuric acid, and further reacted with Li2CO3. Regarding this issue, impacts of various factors under different conditions were investigated, and an orthogonal experimental design method was proposed based on optimization conditions. This method was established through T-6 new century ultraviolet spectrophotometer to determine the influence of different conditions, and develop a best combination based on different microwave powers (w), temperatures (°C), and time lengths (min). In this experiment, the maximum absorption peak was determined by scanning wave length, under which the absorbency was identified and the standard curve was established. In order to determine the optimized synthesis condition of indigotindisulfonate lithium, orthogonal experiment design method was applied combining three levels coupled with four factors. From this study, it is concluded that 550w, 3min, 30°C with an indigo-fuming sulfuric acid concentration ratio of 0.02:1 is the best condition to synthesize indigotindisulfonate lithium.

FeIII chelated organic anode with ultrahigh rate performance and ultra-long cycling stability for lithium-ion batteries

Organic electrodes for rechargeable devices have attracted tremendous attention as a promising alternative in lithium-ion batteries (LIBs). Unfortunately, most of the reported organic anodes face huge challenges in practical application because of the low reversible specific capacity, poor rate performance, and short cycling life. Herein, we facilely chelated the renewable tannic acid (TA) via ferric ions and generated a novel organic anode material (TA-Fe) using in LIBs for the first time. Benefiting from the chelation between ferric ions and catechol groups, which changes the inherent microstructure of TA and inhibits its dissolution in electrolyte, the TA-Fe anodes exhibit outstanding electrochemical performance including high reversible capacity (1016 mAh/g at 0.1 A/g), excellent rate capability, and ultra-long cycling stability (10.0 A/g over 16000 cycles with a capacity retention of 78.8%). Besides presenting a high-performance organic electrode, we expect this work to inspire the preparation of other organic materials for advanced LIBs.

Homology and isomerism effect of aromatic imides as organic anode materials of lithium-ion batteries

Organic materials have been promising materials for “greener and sustainable” lithium-ion batteries due to lightweight, low cost, flexibility, alternative molecular engineering. Six kinds of aromatic imides with different aromatic and aliphatic diamines based on 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) were designed, synthesized and studied as anode materials in rechargeable lithium-ion batteries in this work. Compared with ortho-substituted and meta-substituted phenylenediamine, aromatic imide synthesized by p-phenylenediamine shows excellent electrochemical performance on account of its well-organized structure, which possesses 558 mA h g−1 of discharge capacity after 50 cycles at the current density of 25 mA g−1. Besides, imides with shorter alkyl chain would help improve the proportion of electrochemical active conjugated carbonyl compounds, leading to higher capacity. Thus, imide-based electrode materials can be designed efficiently by symmetrical and straight chain structure and less inactive part to gain optimum molecular structure, making it a promising alternative anode material for rechargeable lithium-ion batteries.

A fast π-π stacking self-assembly of cobalt terephthalate dihydrate and the twelve-electron lithiation-delithiation of anhydrous cobalt terephthalate

Crystalline metal-organic frameworks of divalent transition metal terephthalate belong to a new kind of high-capacity lithium storage materials. In this paper, CoCl2 aqueous solution and CoCl2·6H2O particles are comparatively used as starting materials to react with aqueous lithium terephthalate (Li2TP), resulting in the hierarchical architectures of dihydrate cobalt terephthalate (CoTP·2H2O No.1, No.2) by a solution-based π-π stacking self-assembly, respectively. Each of the two hydrated samples, as well as its well-crystallized anhydrous counterpart (CoTP No.1 or No.2), acquire a specific surface area no bigger than 4.5 m2 g−1 but deliver a reversible capacity no less than 815.0 mAh g−1 at 200 mA g−1 in the 100th cycle. The decreasing order of lithium-storage capability (CoTP·2H2O No.1 < CoTP·2H2O No.2 < CoTP No.1 < CoTP No.2) and its reverse trend of charge-transfer resistance indicate an adverse effect of crystal water, conflicting with the previously demonstrated enhancement of crystal water in inorganic cupric oxalate hydrates. Especially, combining voltage profile with its differential curve clearly reveals a 12-electron transfer lithiation-delithiation mechanism, which explains the ultrahigh reversible capacity (1234.2 mAh g−1, the 350th cycle) of CoTP No.2 structure and indicates a successful approach to the facile preparation of the organic anode material for high-performance lithium-ion batteries.

OXTR brain tissue expression quantitative locus rs237895 moderates the association between maternal childhood maltreatment and non-optimal maternal behavior with implications for offspring socio-emotional development and attachment security

Crystalline metal-organic frameworks of divalent transition metal terephthalate belong to a new kind of high-capacity lithium storage materials. In this paper, CoCl2 aqueous solution and CoCl2·6H2O particles are comparatively used as starting materials to react with aqueous lithium terephthalate (Li2TP), resulting in the hierarchical architectures of dihydrate cobalt terephthalate (CoTP·2H2O No.1, No.2) by a solution-based π-π stacking self-assembly, respectively. Each of the two hydrated samples, as well as its well-crystallized anhydrous counterpart (CoTP No.1 or No.2), acquire a specific surface area no bigger than 4.5 m2 g−1 but deliver a reversible capacity no less than 815.0 mAh g−1 at 200 mA g−1 in the 100th cycle. The decreasing order of lithium-storage capability (CoTP·2H2O No.1 < CoTP·2H2O No.2 < CoTP No.1 < CoTP No.2) and its reverse trend of charge-transfer resistance indicate an adverse effect of crystal water, conflicting with the previously demonstrated enhancement of crystal water in inorganic cupric oxalate hydrates. Especially, combining voltage profile with its differential curve clearly reveals a 12-electron transfer lithiation-delithiation mechanism, which explains the ultrahigh reversible capacity (1234.2 mAh g−1, the 350th cycle) of CoTP No.2 structure and indicates a successful approach to the facile preparation of the organic anode material for high-performance lithium-ion batteries.

Pore-size dominated electrochemical properties of covalent triazine frameworks as anode materials for K-ion batteries.

Two homologous covalent triazine frameworks (CTFs) have been developed for the first time as anode materials for high performance K-ion batteries (KIBs). The two-dimensional sheet-like structure as well as the regular channels in CTFs enable the process of intercalation/deintercalation of K-ions into/from the CTF interlayers reversibly. Particularly, a size effect of the porous structure is found to dominate the K-ion storage behavior. CTF-0 with a smaller pore size displays a higher K-ion storage capacity than CTF-1. Molecular simulations reveal the operation mechanism, showing that the depotassiation process in CTF-0 is exothermic while the depotassiation in CTF-1 is endothermic, which makes the deintercalation of K-ions from CTF-0 more feasible than from CTF-1 and contributes to the higher reversible capacity of CTF-0. This work provides a promising strategy for rational design of high-performance organic anode materials by structural modulation at the molecular scale.

Green and facile synthesis of nanosized polythiophene as an organic anode for high-performance potassium-ion battery

In this work, nanosized polythiophene (PTh) is synthesized via a green and facile method. The obtained nanosized PTh was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller theory (BET) and scanning electron microscopy (SEM). The result indicated that a nanosized, porous and amorphous PTh was synthesized. As an organic anode material for potassium ion battery, the PTh shows excellent performance with a reversible capacity of 58[Formula: see text]mAh[Formula: see text]g[Formula: see text] at 30[Formula: see text]mA[Formula: see text]g[Formula: see text].

(Keynote) Comparison of the Electrode Materials for Li and Na Ion Batteries

Secondary battery is becoming the key enabling technology for 3C products, electric vehicles (EVs) and energy storage system (ESS). Lithium-ion batteries (LIBs) with high energy density are widely used for mobile electronics, EVs and energy storage. Due to the abundant of resources, sodium-ion batteries (SIBs) have been considered as the promising candidate for large-scale energy storage system owing to the economic efficiency. LIBs and SIBs share similar concept and many materials. This presentation will summarize and compare their anode and cathode materials. Carbonaceous materials are commonly used for both of them as anode materials. However, well crystallized graphite is a good anode material for LIBs but not for SIBs. We have made hard carbon from sugar and anthracite for Li+ and Na+ storage. Sn, Sb, Si etc., which can alloy with Li and Na, show higher Na storage capacity. The rate capability of battery electrodes is highly dependent on the grain size, texture, and morphology of the electrode materials. An ordered, high surface area structure of electrochemically active materials on the nano scale can yield enhanced charge/discharge characteristics. Using nano materials as electrodes presents new opportunities for energy density, exceptionally high rate of charge and discharge, high cyclability, and low cost. The spinel Li4Ti5O12, well-known as a ‘zero-strain’ anode for lithium-ion batteries, can also store sodium, displaying an average storage voltage of 0.91 V and a reversible capacity of 155 mAh g1 and presents the best cyclability among all reported oxide-based anode materials. A three-phase separation mechanism, 2Li4Ti5O12 + 6Na+ + 6e- → 2Li7Ti5O12 + Na6LiTi5O12, has been confirmed. Furthermore, we also proposed many organic anode materials for SIBs including: Na2C8H4O4, Na2C6H2O4, Na2C14H6O4. In particular, we resolved the crystal structure of Na2C6H2O4 and found that it consists of alternating Na-O octahedral inorganic layer and π-stacked benzene organic layer in spatial separation. The experiment and calculation results reveal the Na-O inorganic layer provides both Na+ ion transport pathway and storage site, while the benzene organic layer provides electron transport pathway and redox centre. A large variety of cathode materials have been proposed based on the abundant knowledge developed on LIBs. They include layer- and spinel-structured transition metal oxides, and poly-anionic-type compounds. While layer-structured oxides with Co show high capacity for LIBs, the poly-anionic-compounds，spinel-type oxides and organic cathode materials are more promising for wide range of applications. Spinel-type oxides are used for LIBs only and certain nano-layered materials protected their surface and improve their cycling performance even at elevated-temperatures. High-voltage spinel LiNi0.5Mn1.5O4 cathode material has specific energy (~640 Wh/kg) due to the high operation voltage of ~4.7 V. The relatively inexpensive Ni and Mn in LiNi0.5Mn1.5O4 make this cathode material particularly desirable for large-scale applications. The surface regions (~ 2nm) show an irreversible migration of TM ions into lithium tetrahedral sites to form a Mn3O4-like structure. When the surface LiNi0.5Mn1.5O4 was modified by coating and superficial doping, the cycling performance of the material at elevated temperatures has been much improved and the Coulombic efficiency of discharge/charge is also obviously increased. Theoretical calculations analyses reveal that the stability of O at surface layer is enhanced by those surface modifications. Many layered oxide cathode materials with a general formula of NaxMO2 (M = Ni, Co, Mn, Fe, Cr, etc.) have attracted great attention for SIBs. We discovered that a novel Cu2+/Cu3+ redox couple is electroactive in Na containing layered oxides. On the basis of this important finding, we designed a new layered oxide, O3-Na0.9[Cu0.22Fe0.30Mn0.48]O2, showing unexpectedly superior stability against moisture and excellent electrochemical cycling stability. The material delivers a reversible capacity of 100 mAh/g with an average voltage of 3.2 V and stable cycling. A prototype sodium-ion pouch cell using our Cu based cathode and anthracite derived carbon anode is demonstrated to have an energy density of 117 Wh/kg and good cycling as well as high safety. The perspective of future practical application will be discussed based the comparison of materials.

Non-Conjugated Dicarboxylate Anode Materials for Electrochemical Cells.

Classical organic anode materials for Na-ion batteries are mostly based on conjugated carboxylate compounds, which can stabilize added electrons by the double-bond reformation mechanism. Now, 1,4-cyclohexanedicarboxylic acid (C8 H12 O4 , CHDA) with a non-conjugated ring (-C6 H10 -) connected with carboxylates is shown to undergo electrochemical reactions with two Na ions, delivering a high charge specific capacity of 284 mA h g-1 (249 mA h g-1 after 100 cycles), and good rate performance. First-principles calculations indicate that hydrogen-transfer-mediated orbital conversion from antibonding π* to bonding σ stabilize two added electrons, and reactive intermediate with unpaired electron is suppressed by localization of σ-bonds and steric hindrance. An advantage of CHDA as an anode material is good reversibility and relatively constant voltage. A large variety of organic non-conjugated compounds are predicted to be promising anode materials for sodium-ion batteries.

Organic vanadium oxy-acetylacetonate as electro-active anode material with high capacity and rate performance for lithium-ion batteries

Vanadium oxy-acetylacetonate (VO(acac)2) was originally explored as an organic anode material for lithium-ion batteries (LIBs) with high capacity and rate performance. Specifically, the prepared VO(acac)2 has delivered capacity of 620 mA h g−1 at current density of 100 mA g−1 with nearly 100% coulombic efficiency during cycling. Furthermore, the cell exhibits good ultralong cycle stability and performs capacity of 508.5 mA h g−1 after 1000 cycles under 1000 mA g−1. Therefore, in the absence of any structure manipulation or conductive additives, the pristine VO(acac)2 shows high promises as advanced anode candidate of high capacity for LIBs.

Reversible Redox Chemistry of Azo Compounds for Sodium‐Ion Batteries

AbstractSustainable sodium‐ion batteries (SSIBs) using renewable organic electrodes are promising alternatives to lithium‐ion batteries for the large‐scale renewable energy storage. However, the lack of high‐performance anode material impedes the development of SSIBs. Herein, we report a new type of organic anode material based on azo group for SSIBs. Azobenzene‐4,4′‐dicarboxylic acid sodium salt is used as a model to investigate the electrochemical behaviors and reaction mechanism of azo compound. It exhibits a reversible capacity of 170 mAh g−1 at 0.2C. When current density is increased to 20C, the reversible capacities of 98 mAh g−1 can be retained for 2000 cycles, demonstrating excellent cycling stability and high rate capability. The detailed characterizations reveal that azo group acts as an electrochemical active site to reversibly bond with Na+. The reversible redox chemistry between azo compound and Na ions offer opportunities for developing long‐cycle‐life and high‐rate SSIBs.

Reversible Redox Chemistry of Azo Compounds for Sodium-Ion Batteries.

Sustainable sodium-ion batteries (SSIBs) using renewable organic electrodes are promising alternatives to lithium-ion batteries for the large-scale renewable energy storage. However, the lack of high-performance anode material impedes the development of SSIBs. Herein, we report a new type of organic anode material based on azo group for SSIBs. Azobenzene-4,4'-dicarboxylic acid sodium salt is used as a model to investigate the electrochemical behaviors and reaction mechanism of azo compound. It exhibits a reversible capacity of 170 mAh g-1 at 0.2C. When current density is increased to 20C, the reversible capacities of 98 mAh g-1 can be retained for 2000 cycles, demonstrating excellent cycling stability and high rate capability. The detailed characterizations reveal that azo group acts as an electrochemical active site to reversibly bond with Na+ . The reversible redox chemistry between azo compound and Na ions offer opportunities for developing long-cycle-life and high-rate SSIBs.

Sodium Naphthalene Dicarboxylate Anode Material for Inorganic-Organic Hybrid Rechargeable Sodium-Ion Batteries

Currently, finding a suitable anode material for sodium-ion batteries (NIBs) is the major challenge as graphite is not an ideal anode candidate. Recently, organic anode materials hold promise as potential alternatives. In this study, naphthalene based dicarboxylate (Na2-NDC) has been explored as anode material for NIBs. The electrochemical sodiation/desodiation process of Na2-NDC is a biphasic reaction and it shows a good capacity retention even after 100 cycles. Ex-situ XRD studies reveal structurally robust nature of Na2-NDC during sodiation/desodiation process. Moreover, the Na2-NDC anode was paired with Na3V2O2(PO4)2F/rGO cathode and demonstrated a full cell for the first time.