The World Meteorological Organization (WMO) announced that, under the influence of greenhouse gases, the world's average temperature has reached the worst heat wave in the past five years. Such signs of global warming and its accelerating effects have drawn widespread global attention. To prevent a dramatic increase in global warming, efforts are being made to minimize the use of fossil fuels for power generation and fully utilize renewable and clean energy sources such as solar and wind power. However, the power output of solar and wind power fluctuates with seasons and weather conditions. When connected to the power grid, the shutdown of synchronous generators in thermal power plants can cause power instability in the system. To address this issue, active research is underway on the rational storage of electrical energy and the optimal energy storage system.
Energy storage is a prerequisite for achieving multi-energy, low-carbon, safe, and efficient energy, and is an important foundation for supporting the construction of new power systems.
Figure 1 shows the characteristics of various energy storage devices. As a lithium-ion battery, lithium cobalt oxide (LCO) batteries have a high energy density (200 Wh/kg), making them suitable for smartphones and PCs. However, LCO batteries involve cobalt, a strategic material, and pose a safety hazard of thermal explosion, which urgently needs to be addressed. As a replacement, lithium iron phosphate (LFP) batteries have gained attention due to their high-capacity energy storage capabilities. With an energy density of around 100 Wh/kg, they are already being used in Tesla electric vehicles and are being sold. However, LFP batteries can only operate within a temperature range of 0–45°C, making them unsuitable for cold regions. Furthermore, in the high temperatures of hot summers, cooling measures and precise temperature control are necessary.
