Improving the Discharge Rate of Co₃O₄-Based Thermochemical Energy Storage Material with Eutectic Doping of Zr

Abstract

Co-based oxides are promising thermochemical energy storage (TCES) media as they exhibit long-term cycle stability, which offers a solution for addressing the problems associated with the intermittent nature of zero-carbon renewable energy sources. It is crucial to improve the charging rate of Cobased oxides to facilitate a rapid load increase in power plants. This study evaluates the impact of Zr doping on the charging rate of Cobased oxides and examines the mechanism associated with the enhancement effects. Zr-doped Co-based oxides with a cubic microstructure were synthesized. A low Zr content through eutectic doping resulted in the generation of a single-phase structure, which inhibited Co 3 O 4 nucleation and growth and was enriched in Co 3+ and oxygen on the surface. A stable TCES conversion efficiency was maintained during the process for over 20 charging and discharging cycles. The mechanism behind this enhancement was also investigated by using density functional theory calculations. The results indicated that eutectic doping with Zr facilitated the electron transfer and distribution. The process was primarily centered on the Zr atom. Consequently, this promoted the adsorption of Co atoms and O 2 . A significant reduction in the dissociation energy barrier of O 2 during the crystal reconstruction process was observed. The results reported herein help us to understand the potential industrial application of Co-based oxide media in TCES systems.

Deagglomeration Phosphorus Doping in Ferromanganese Oxide for Thermochemical Energy Storage

“…Research has focused on mitigating the sintering of metal oxide materials, including doping with metals and metal oxides, − where the particle size decreases at high temperature. Sintering can be suppressed by reducing surface energy, but the effect of changes in surface energy during the reaction process is not clear; it may not be suitable for thermal storage materials…”

Li4SiO4-Based Heat Carrier Derived from Different Silica Sources for Thermochemical Energy Storage

“…Up to now, a series of materials have been reported to act as heat carriers for TCES applications, including hydroxides (e.g., CaO/Ca(OH) 2 ) [14,15], oxides (e.g., Fe 2 O 3 /Fe 3 O 4 ) [16,17], carbonates (e.g., CaO/CaCO 3 ) [18][19][20], and sulfates (e.g., MgO/MgSO 4 ) [21]. Among them, the Li 4 SiO 4 -based heat carrier, which operates at the 600-900 • C medium temperature region and possesses a theoretical storage density of 784.3 kJ/kg, has been considered a potential candidate [22,23].…”