Chemical in three conditions: overcharged, undercharged and left discharged

Chemical
batteries used in automotive application:

Lead-Acid
Battery:

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

A type of
battery which is commonly used for to start automotive, ignition and lighting.
Following are the chemical reactions in a cell:

Positive Electrode

Negative Electrode  

The cation and anion
produces current.

(a)  
                                                                  (b)

Figure 1: Fully charged (a) and fully
discharged (b) cell

Construction:  Negative group and positive group are constructed
as plates and separator is placed in between the both plates. The separator is
porous in nature which do not let happen short circuiting in the
electrochemical cell. The construction of the plates are spongy in nature it
means plates have more surface area. And it is well known that more surface area
means more power capability. It is also possible to increase thickness of cell
plates in terms of increase the energy capacity.

Figure 2 Multiple Plate arrangement of
electrochemical cell

 

Applications

To start automotive, Ignition,
lighting

 Advantages

Manufacturing is simple
Less cost / Wh
Good performance in low and high
temperature
Self-discharge is low

Limitations

Aging mechanism “Sulfation”
Bad for environment  
Poor weight and energy ratio
Slow charging: takes 14-16 hrs to full
charge
Water requirement for flooded type
Transportation difficulties in flooded
type

 

Aging : the phenomenon of sulfation is called aging. Production of
sulfate in three conditions: overcharged, undercharged and left discharged is
cause of sulfation.

Sealed Lead Acid (SLE) and Valve
Regulated Lead Acid (VRLA) are
different from flooded type as these type of batteries contains less amount of
electrolyte. Loss of water is less in these type of batteries because packing
design decreases vents less gases at the time of charging. As the these are
also called maintenance free batteries. These batteries operate a higher
voltage than flooded batteries (2.25). The limitations of these batteries are
less mature technology of SLA/VRLA and existence of thermal runaway.  

Figure number : Comparison between
flooded lead acid and VRLA

 Nikil-Metal
Hydride: NiCd
based batteries replased by NiMH because cadmium is very toxic and presence of
memory effect. Likewise cost of NiMH is less.

 

For
NiMH type of batteries M is intermetallic compound of AB5 or AB2. Where for A
and B are combination of following metals: (1)AB5 (2)AB2

 

AB5

A

B

La

Ca

Pr

Nd

Ni

Co

Mn

Al

AB2

A

B

Ti

V

Zr

B

Ni

Co

Cr

Al

Mn

Sn

 

The
chemical reaction are as follows:

Positive Electrode

Negative Electrode  

              
Discharge=1.35 V

 

 

Figure number : NiMH cell operation

 

Reason
of aging:

(1)Expansion
during cycling and contraction during usage produces mechanical forces again
and again which generate breakdown in particles.

(2)
Increment of resistive layer because of corrosion

(3)
In condition of overcharge and over discharge production of gas

(4)
Self discharge

 

 Lithium Ion Batteries:

Positive Electrode

Negative Electrode  

              
Discharge=3.7 V

 

 

 

 

 

Figure Number: Li Ion cell operation  

 

Sodium
Nickel Chloride

 

Positive Electrode

Negative Electrode  

              
Discharge=2.58 V

 

 

x

Hi!
I'm Angelica!

Would you like to get a custom essay? How about receiving a customized one?

Check it out