الفهرس 
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Abstract
The objective of this work is to study the effect of using composites based on modified Egyptian clays on the performance of prepared supercapacitors electrodes.
Global warming and the limited availability of fossil fuels have a significant impact on the global economy and ecosystems, making the need for efficient energy storage and green energy substitution one of the most important concerns of the modem world*11. Unconventional energy storage systems like supercapacitors, batteries, fuel cells, could be the solution for that problem*2*. By far the battery technology is the most evolved and economical option for electrical energy storage. Yet, its short cycle life, slow charging and bulky design hindered it from entering the market of high power electric vehicles, lightweight devices, portable electronics, and transparent and flexible displays. Besides, those batteries contain toxic and hazardous materials, which cause harm to the environment and need special precautions for disposing of it*3*. Recently, Li-ion technology gained prominence for being highly compact, lightweight and lower in toxicity. However, lower values of power density and the risk of thermal decomposition at elevated temperatures still hinder its implementation in a broader context*4*. On the other hand, supercapacitors are a new class of devices that run by a simple mechanism. They provide excellent cyclic stability as well as ultra-fast charging and discharge. These devices are lightweight, nontoxic and environmentally friendly, unlike batteries*5*.
In Figure 1.1, the plots of power density versus energy density, also called Ragone plots, are shown for the previously mentioned electrical energy storage. Supercapacitors are in a critical position in the plot as they are known to be a bridge between traditional capacitors and batteries. It can provide high power density compared to batteries but smaller than traditional capacitors. However, it gives lower energy densities compared to batteries but higher than conventional capacitors. Table 1.1 shows a comparison between different properties of capacitor, supercapacitor and battery*61.
Energy density.