6. Perovskites
Perovskites is a family name of a group of materials and is also the mineral name of calcium titanate (caTiO3)
having a structure of ABO3 . Many piezoelectric ceramics possess this structure, such as Barium Titanate
(BaTiO3), Lead Zirconate Titanate (PZT), Lead Titanate (PbTiO3), etc.
Peroviskite Structure
7. Battery Technology
Introduction :
An electrochemical cell is a chemical reactor containing reactive and electrically conductive
materials which react in a controlled manner to produce direct current electricity. There are 2 types of cells:-
1. Primary Cells- Here the electrochemical reaction is not reversible. Therefore it cannot be recharged by
passing current in opposite direction. Primary Cells are discarded after single use.
2. Secondary Cells- Here the electrochemical reaction is reversible. It can be charged
back to its original capacity by passing a current in the opposite direction and used again. This charging
and discharging of the battery may occur many times depending on the battery technology.
8. The Li – ion battery
Voltage range – 3.5 to 5.5 volt
Energy given - 41.5KJ/g Li
9. The Ni-Cd battery
Voltage Range is 1.1 to 1.5 volt
• A 100 mAh battery takes 120 mAh to charge
• The safe temperature range when in use is
between −20°C and 45°C. During charging
11. • This process allows NiMH cells to remain sealed in normal
operation and to be maintenance-free.
• A fully charged cell supplies an average 1.25 V/cell during
discharge
• A freshly charged AA NiMH cell in good condition is about
1.4 volts.
• Charging voltage is in the range of 1.4–1.6 V/cell
16. Electromechanical Coupling Factor
The electromechanical coupling factor, k, is an indicator of the
effectiveness with which a piezoelectric material converts
electrical energy into mechanical energy, or converts
mechanical energy into electrical energy. The first subscript to k
denotes the direction along which the electrodes are applied;
the second denotes the direction along which the mechanical
energy is applied, or developed.
Kp = (fn – fm)/fm
17. Observations:
each element total
Material shape area (mm2) d33(pC/N) capacitance (nF) max. V avg. V
1 circular 50.26 2260 36 1.5 1.15
2 circular 314.16 2610 17.76 1.2 1
3 circular 314.16 2610 15.89 1.2 1
4 square 100 4098 1.58 3.8 2.5
Ideal V
applied force
(N)
height
(mm)
no. of
element avg.V /Area
Max.
Idealist
avg. Current
/area
10.3 70 2.5 9 0.023 0.14563107 4.996
8.6 70 2.5 9 0.0032 0.13953488 0.923
8.6 70 2.5 9 0.0032 0.13953488 0.923
18.39 70 6 9 0.025 0.20663404 4.553
21. Conclusions
Charged Li-ion mobile battery of 1600 mAH from 39% to
48% is just in 1kM of travel. That is around 1300 steps for
common man and also we had used of 56 kg person to
charge.
