MES RK PRoject 2020-2022
“Sodium batteries for large-sized energy storage devices in the renewable energy sector of Kazakhstan” (IRN AP08856725)
Project goal:
Development and production of an optimized prototype of a sodium battery based on aqueous electrolyte for large-scale energy storage devices. During the implementation of the project, it is planned to synthesize, optimize, modify and test cathode and anode materials, select an electrolyte with a wide stability window, and select current leads.
Results achieved:
1) Measurements were carried out of the viscosity, density and electrical conductivity of solutions of sodium perchlorate in water in a wide range of concentrations up to a saturated solution; an extreme dependence of electrical conductivity on the concentration of sodium perchlorate and a monotonic increase in dynamic viscosity with increasing concentration are shown. Calculations of transfer parameters in solutions of different concentrations were carried out.
2) The influence of sodium perchlorate concentration on the width of the window of electrochemical stability potentials has been established; its significant increase in the region close to saturation has been shown.3) A selection of additives was made from the group of surfactants of various natures.
4) Several types of iron hexacyanoferrates with different structure, particle size and electrochemical characteristics were synthesized and analyzed. Data on the capacities of the synthesized materials at various current densities were obtained, and the kinetic parameters of the synthesized materials (diffusion coefficients) were calculated. Based on the analysis of the data obtained, the material with the greatest stability, capacity and speed characteristics was selected. As a result of using a new method of washing the material, a purer finely dispersed hexacyanoferrate was obtained. The resulting CV curves at different scan rates show the ability of the material under study to undergo a rapid discharge/charge process with low capacity losses as the charge rate increases.
5) Active NaTi2(PO4)3 (NTP) has been synthesized, having a thin carbon coating formed during the carbothermal decomposition of tartaric acid. The results of electron microscopy show that aggregated NTP particles were obtained, consisting of sphere-like nanoparticles d ≈ 500 nm. The obtained value of the electrochemical stability window determined on the graphite foil is 2.5 V. The synthesized NTP is determined to have a capacity of 81 mAh/g, calculated from the CV results at 5 mV/s. The results of long-term cycling carried out by the galvanostatic method indicate acceptable stability of the material over 150 cycles, retaining 80% of the original capacity with a Faraday efficiency of the process of 97.8%. Based on the results of electrochemical tests, it was determined that the resulting carbon coating significantly improves the volumetric conductivity of the electrode, which affects the increased capacity of the coated material.
2) The influence of sodium perchlorate concentration on the width of the window of electrochemical stability potentials has been established; its significant increase in the region close to saturation has been shown.3) A selection of additives was made from the group of surfactants of various natures.
4) Several types of iron hexacyanoferrates with different structure, particle size and electrochemical characteristics were synthesized and analyzed. Data on the capacities of the synthesized materials at various current densities were obtained, and the kinetic parameters of the synthesized materials (diffusion coefficients) were calculated. Based on the analysis of the data obtained, the material with the greatest stability, capacity and speed characteristics was selected. As a result of using a new method of washing the material, a purer finely dispersed hexacyanoferrate was obtained. The resulting CV curves at different scan rates show the ability of the material under study to undergo a rapid discharge/charge process with low capacity losses as the charge rate increases.
5) Active NaTi2(PO4)3 (NTP) has been synthesized, having a thin carbon coating formed during the carbothermal decomposition of tartaric acid. The results of electron microscopy show that aggregated NTP particles were obtained, consisting of sphere-like nanoparticles d ≈ 500 nm. The obtained value of the electrochemical stability window determined on the graphite foil is 2.5 V. The synthesized NTP is determined to have a capacity of 81 mAh/g, calculated from the CV results at 5 mV/s. The results of long-term cycling carried out by the galvanostatic method indicate acceptable stability of the material over 150 cycles, retaining 80% of the original capacity with a Faraday efficiency of the process of 97.8%. Based on the results of electrochemical tests, it was determined that the resulting carbon coating significantly improves the volumetric conductivity of the electrode, which affects the increased capacity of the coated material.
Contacts
Visiting hours 9.00-18.00, Mon-Fri
• Mal'chik Fedor Igorevich is a leading “researcher”, head of the laboratory “Electrochemical Production Technologies”.
• Phone: +7 707 244 2236
• Е-mail: frodo-007@mail.ru
• Phone: +7 707 244 2236
• Е-mail: frodo-007@mail.ru
•Address: Almaty city, Al-Farabi Avenue 71/23
