Enabling High Performance Calcium-Ion Batteries from Prussian Blue and Metal–Organic Compound Materials

Abstract

Full cell calcium-ion batteries (CIBs) were fabricated from Prussian blue and metal–organic compound (MOC) materials and characterized. The anode materials were prepared via the simple precipitation of a nickel salt and various organic sodium salts (C6H6‑x‑y (COONa) x (NH2) y ). The OH vibration in FTIR results indicated the partial hydrolysis of Ni-based MOCs during the synthesis. Particularly, the addition of NH2 groups in the ligand increased the steric hindrance; thus, the partial hydrolysis of the Ni-based MOC was inhibited. When the anode material was a partially hydrolyzed MOC (Ni­(OH)­[C6H4(COOH)­(COO)]), the full cell gave an initial discharging capacity of 82 mAh g–1 and a capacity retention of 62% at 0.1 A g–1 after 100 cycles, while the Coulombic efficiency was maintained at approximately 95.4%. The cell obtained from an NH2-functionalized MOC (Ni­[C6H4(NH2)­(COO)2]) delivered an initial discharging capacity of 86 mAh g–1 and a capacity retention of 77% at 0.1 A g–1 after 100 cycles, while the Coulombic efficiency was maintained at approximately 97%. The impedance tests suggested that Ni-based MOCs had typically low resistance, which is essential to achieve stable full cell CIBs.

Proton-assisted calcium-ion storage in aromatic organic molecular crystal with coplanar stacked structure

“…8f ), which is among the longest reported for CIB systems (both aqueous and nonaqueous) (Fig. 8g and Supplementary Table 2 ), including Sn//graphite 18 , Sn//Activated carbon (AC) 17 , PNDIE//KCuFe(CN) 6 24 , KFeFe(CN) 6 //Ni-based metal–organic compound 44 , NH 4 V 4 O 10 //manganese 2-aminoterephthalate (Mn-bdcNH 2 ) 53 , Mg 0.25 V 2 O 5 •H 2 O//Activated carbon cloth (ACC) 54 , graphite//Ca 19 , etc.

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“…The calculated diffusion coefficient of the Ca 2+ ions ( D ) in the PT anode during discharging and charging is in the range of 10 −8 –10 –11 cm 2 S –1 (Fig. 3e ), which is significantly higher than that of Li + in LiFePO 4 (10 −14 –10 − 16 cm 2 S −1 as determined by GITT 40 ) and Li 4 Ti 5 O 12 (10 –11 –10 –12 cm 2 S − 1 as determined by potentiostatic intermittent titration technique 41 and 10 –12 –10 −13 cm 2 S −1 as determined by CV 42 ), Zn 2+ in α-MnO 2 (10 −15 –10 –17 cm 2 S −1 as determined by GITT) 43 , Ca 2+ in other materials (e.g., Ca 2+ in Ni-based metal-organic compound, 5.3 × 10 –14 cm 2 S −1 as determined by electrochemical impedance spectroscopy) 44 . The high apparent diffusion coefficient of Ca 2+ ions (D) in the PT anode can be ascribed to its weakly stacked layered structure with 1D molecular channels, which provides an efficient Ca 2+ ion diffusion pathway, thus leading to enhanced reaction kinetics of PT during the electrochemical reaction process.…”

A Computational Comparison of Ether and Ester Electrolyte Stability on a Ca Metal Anode

“…Since the publication of Ponrouch et al, there have been numerous reports of viable Ca-ion electrolytes, ranging from organic solvents [10][11][12][13][14] to ionic liquids [15,16] and polymers [17]. With several examples of successful Ca-ion cathodes [18][19][20][21], a cyclable Ca-ion rocking chair battery is within reach; in fact, there are already some functional examples of such a setup [14,22]. These successes motivate further investigation of CIB electrolytes, which remain a limiting factor in battery performance.…”

High Performance Voltage Tailorable Room-temperature Ca-metal Batteries

“…For example, Prussian blue analgues, layered transition metal oxides and Van der Waals-bound layered transition metal sul des featured with large tunnel structure or interlayer spacings have been reported as good cathodes, while tin, graphite carbon microbeads (MCMBs), and atitivated carbon cloth served as the anodes. [10][11][12][13][14][15][16] For example, MnFe(CN) 6 //calciated-Sn battery held a capacity of ~50 mAh g -1 (based on the weight of the cathode) at 0-4 V after 30 cycles through a Ca 2+ /Na + hybrid intercalation mechanism. 10 A reversible capacity of ~ 75 mAh g -1 due to Ca 2+ insertion/extraction at 0.01-2V stably persisting for 100 cycles was reported for Na-doped ammonium vanadium oxide (NH 4 V 4 O 10 ) cathode and Ni-based framework anode system.…”