**4. Conclusion**

The efficiency of a PEM cell is dependent on the current density during operation. While a higher current density is crucial to cut down the start-up cost, a lower current density is needed to cut down the cost of operation. Both factors have to be taken into consideration [33]. Different types of electrolytes can be deployed in an EL cell: an alkaline electrolysis (AEL) cell works with a basic liquid electrolyte. In a proton exchange membrane (PEM) EL cell, an acidic ionomer—a process often called solid polymer electrolysis (SPE)—is used, and a high-temperature (HT) EL cell has a solid oxide as the electrolyte. The schematic diagram of

the alkaline electrolysis cell is presented in **Figure 4**.

**Figure 4.** Schematic diagram of the alkaline electrolysis cell [34].

**Figure 3.** Schematic diagram of PEM electrolysis cell [33].

30 Advances In Hydrogen Generation Technologies

In this chapter, hydrogen production from membrane electrolysis is discussed in detail. Hydrogen production from membrane water splitting technologies possesses great potential as a sustainable hydrogen source. Previous research focused mainly on Nafion-based membrane, but with the advancement in the research, a better and cheaper membrane can be used without compromising on the output of hydrogen production. Composite membrane provides better performance in terms of durability, heat resistance, hydrogen production, and purity.
