All Organic Sodium‐Ion Batteries with Na₄C₈H₂O₆

Abstract

Developing organic compounds with multifunctional groups to be used as electrode materials for rechargeable sodium-ion batteries is very important. The organic tetrasodium salt of 2,5-dihydroxyterephthalic acid (Na 4 DHTPA; Na 4 C 8 H 2 O 6 ), which was prepared through a green one-pot method, was investigated at potential windows of 1.6-2.8 V as the positive electrode or 0.1-1.8 V as the negative electrode (vs. Na + /Na), each delivering compatible and stable capacities of ca. 180 mAh g À1 with excellent cycling. A combination of electrochemical, spectroscopic and computational studies revealed that reversible uptake/removal of two Na + ions is associated with the enolate groups at 1.6-2.8 V (Na 2 C 8 H 2 O 6 / Na 4 C 8 H 2 O 6 ) and the carboxylate groups at 0.1-1.8 V (Na 4 C 8 H 2 O 6 /Na 6 C 8 H 2 O 6 ). The use of Na 4 C 8 H 2 O 6 as the initial active materials for both electrodes provided the first example of all-organic rocking-chair SIBs with an average operation voltage of 1.8 V and a practical energy density of about 65 Wh kg À1 .Room-temperature rechargeable sodium-ion batteries (SIBs) have recently become a research focus because sodium has a high natural abundance, low cost, and is more environmentally benign than lithium. [1][2][3] However, similar to Li-ion batteries (LIBs), an overwhelming majority of host materials in SIBs are based on depletable transition-metal inorganic compounds, [4][5][6][7][8][9] which are generally prepared from limited mineral resources through energy intensive processing. The development of new types of green and sustainable Na-storage materials is therefore necessary for safer and lessexpensive rechargeable SIBs.One of the innovative strategies is shifting from traditional inorganic compounds to new organic alternatives. Organic concept provides potential advantages such as structural diversity and flexibility, molecular level controllability, eco-efficient processability and resource renewability. [10][11][12][13] Indeed, a series of organic compounds have been studied as the electrode materials of energy-storage devices such as LIBs and supercapacitors. [14][15][16][17][18][19][20][21][22][23][24] Recently, some of them have been demonstrated to have high specific capacity, cycling stability, and high rate capability, making them promising applications in SIBs. [25][26][27][28][29][30][31] However, there are only a few reports on sodium-ion full cells based on organic electrode materials. Abouimrane et al. [32] first incorporated a disodium terephthalate-based organic anode material into sodium-ion full cells, but a conventional transition-metal cathode material (Na 0.75 Mn 0.7 Ni 0.23 O 2 ) was still needed. The first and only all organic sodium-ion cell based on a polymeric cathode and anode was constructed by Yang and co-workers, [33] showing a specific capacity of ca. 55 Wh kg À1 with an average voltage of 1.8 V. In this system, a p-doped polymer was used as a cathode material, which experiences the pdoping/de-doping mechanism of large electrolyte anion...

Biologically inspired pteridine redox centres for rechargeable batteries

“…The limited cyclability could be attributable to the non-optimized Na electrolytes of the cell and the large strain of the electrode materials during the insertion of large sodium ions, which may induce the isolation of the active materials from the electrodes. While further studies are required, the sodium-organic battery system is promising for sustainable energy storage systems, since it is based on abundant sodium elements on earth and does not contain transition metals [38][39][40] . The utilization of diazabutadiene redox cycling should provide potential opportunities for sodium-organic battery systems.…”

Understanding sodium-ion diffusion in layered P2 and P3 oxides via experiments and first-principles calculations: a bridge between crystal structure and electrochemical performance

“…[2][3][4][5][6] Rechargeable sodium-ion batteries have chemical storage mechanisms similar to their lithium-ion counterparts and are expected to be low cost and chemically sustainable as a result of an almost infinite supply of sodium. [7][8][9][10][11][12][13][14][15] Meanwhile, the feasible replacement of Cu with Al current collectors (an alloying reaction does not occur between Na and Al) will further reduce the substantial costs and weight for nextgeneration batteries.Layered sodium oxide Na x MeO 2 (Me = 3d transition metal) materials, owing to their large specific capacity and reversible insertion/ …”

From an Enhanced Understanding to Commercially Viable Electrodes: The Case of PTCLi4 as Sustainable Organic Lithium‐Ion Anode Material

“…[6,8] This issue is commonly addressed inter alia by introducing ionic moieties, or by partial lithiation of the starting molecule. [6][7][8]14] Following these considerations, studies on carbonyl-based alternative anodes cover the whole range from lithium/sodium terephthalates [15][16][17][18][19][20][21][22] and benzenediacrylate [23] over naphthalene carboxylates [15,[24][25][26] to perylene carboxylates. [27][28][29][30] Although such an extension of the aromatic core to more than one phenyl ring leads to a decrease in specific capacity as a direct result of the increasing molecular mass, the amelioration of the π-electron delocalization positively affects the rate capability and cycling stability.…”