The paper describes factors influencing the development of electricity storage technologies. The results of the energy analysis of the electric energy storage system in the form of hydrogen are presented. The analyzed system consists of an electrolyzer, a hydrogen container, a compressor, and a PEMFC fuel cell with an ion-exchange polymer membrane. The power curves of an electrolyzer and a fuel cell were determined. The analysis took the own needs of the system into account, i.e. the power needed to compress the produced hydrogen and the power of the air compressor supplying air to the cathode channels of the fuel cell stack. The characteristics describing the dependence of the efficiency of the energy storage system in the form of hydrogen as a function of load were determined. The costs of electricity storage as a function of storage capacity were determined. The energy aspects of energy accumulation in lithium-ion cells were briefly characterized and described. The efficiency of the charge/discharge cycle of lithium-ion batteries has been determined. The graph of discharge of the lithium-ion battery depending on the current value was presented. The key parameters of battery operation, i.e. the Depth of Discharge (DoD) and the State of Charge (SoC), were determined. Based on the average market prices of the available lithium-ion batteries for the storage of energy from photovoltaic cells, unit costs of electrochemical energy storage as a function of the DoD parameter were determined.
The second decade of the 21st century is a period of intense development of various types of energy storage other than pumped-storage hydroelectricity. Battery and thermal storage systems are particularly rapidly developing ones. The observed phenomenon is a result of a key megatrend, i.e. the development of intermittent renewable energy sources (IRES) (wind power, photovoltaics). The development of RES, mainly in the form of distributed generation, combined with the dynamic development of electric mobility, results in the need to stabilize the grid frequency and voltage and calls for new solutions in order to ensure the security of energy supplies. High maturity, appropriate technical parameters, and increasingly better economic parameters of lithium battery technology (including lithium-ion batteries) result in a rapid increase of the installed capacity of this type of energy storage. The abovementioned phenomena helped to raise the question about the prospects for the development of electricity storage in the world and in Poland in the 2030 horizon. The estimated worldwide battery energy storage capacity in 2030 is ca. 51.1 GW, while in the case of Poland it is approximately 410.6 MW.
The aim of these studies was to obtain single phase cubic modification of Li7La3Zr2O12 by mechanical milling and annealing of La(OH)3, Li2CO3 and ZrO2 powder mixture. Fritsch P5 planetary ball mill, Rigaku MiniFlex II X-ray diffractometer, Setaram TG-DSC 1500 analyser and FEI Titan 80-300 transmission electron microscope were used for sample preparation and investigations. The applied milling and annealing parameters allowed to obtain the significant contribution of c-Li7La3Zr2O12 in the sample structure, reaching 90%. Thermal measurements revealed more complex reactions requiring further studies.