1.1 Primary Batteries

Primary batteries are batteries in which the redox reaction occurs only once and after significant period of time battery becomes useless and cannot be reused again. A dry cell or Leclanche cell is one such example of a primary battery. 

Construction:

1. A zinc container ( also acting as anode)

2. A Graphite (acting as a cathode) surrounded by powdered manganese dioxide and carbon

3. Ammonium chloride (NH4Cl) and zinc chloride (ZnCl2) paste filling the entire volume

Working:

Redox reactions that take place are:

1 At anode side : 

2.At cathode side : 

This cell has a potential of 1.5 V. (approx)

1.2 Secondary Batteries

A secondary cell is a cell which can be used again and again. It can be recharged by passing current through it in the opposite direction. Normally it can undergo a large number of discharging and charging cycles.

A simplest example is a lead storage battery.It is most commonly used in automobiles and invertor applications.