No abstract

No abstract

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.

Gradually eradicating petrolic use is therefore the correct direction for maintaining the environment of the earth. Developing energy storage and saving energy consumption is the key to maintaining a good life. Currently, the lithium-ion battery is one of the best choices for the use of vehicles. However, the energy density of the lithium-ion batteries on current developments is less than 300 Wh kg -1 , which is restricted by the capacity of electrode active materials.Si has the maximum theoretical capacity (4000 mAh g -1 ) compared with the graphite (372 mAh g -1 ) and Li 4 Ti 5 O 12 (175 mAh g -1 ). However, Si can only be used in small amounts as an additive (less than 10 wt%) in commercial battery owing to the problems of volume expansion [6,7] and electrochemical irreversibility. [8,9] In terms of previous discussions, the repeatable pulverization of Si during cycling is the key in decaying the performance. [10,11] With the volume expansion and the pulverization, the new surface area of Si is continuously generated and contacts electrolyte for more solid electrolyte interphase (SEI) formation, which increases the impedance and consumes lithium ions significantly. Moreover, 300-400% volume change of Si during cycling makes it difficult for battery design. Several researches have been investigated for solving those problems of Si such as carbon coating, [12] element Silicon (Si) has the maximum capacity compared with the conventional graphite, which can dramatically increase the energy density of the battery. However, due to some tremendous drawbacks of Si material such as electrochemical irreversibility and volume expansion on alloy reaction, pure Si cannot be used in large quantities in the anode electrode. In this research, a polymer brush core-shell structure (PBCS) on Si nanoparticle provides three significant functions because of the intramolecular effect of hydrogen bonding with PBCS and the binder delivers a good dispersion in the slurry, a mechanical protection during cycling, and excellent ionic conductivity for highrate tests. The carbonyl groups of polymer brush on Si surface are fabricated to enhance lithium-ion diffusion and the adjustment of attraction and repulsion by intramolecular hydrogen bonding effect with binder in between each Si particles. The PBCS-Si electrode shows the first coulombic efficiency is 87.1%; the retentions are 92.5% (0.1C/ 0.1C) for 200 cycles and 86.2% (0.5C/ 0.5C) for 400 cycles. Operando TXM displays that the PBCS structure significantly protects the nano Si from cracking owing to the high elastic function and intramolecular hydrogen bonding effect of the PBCS. With this novel PBCS-Si material, a high energy density lithium-ion battery can be expected.

No abstract