About
Rechargeableable Battery
There
are five types of rechargeable batteries commercially available.
The following table compares their performance and application.
Currently the most popular rechargeable batteries are Ni-Cd,
Ni-MH and Li-Ion in consumer electronic industry, which are
among our major products.
Using
rechargeable battery can save Environmental
and save your money. For example, one AA size NiMH battery can
be used at least 500 times and equal to 500 pcs
AA alkaline battery, it cost you less than $0.002 for each time. |
Performance Comparison
of various Rechargeable Batteries |
| Parameters |
Lead
acid |
Ni-Cd |
Ni-M-H |
Liquid
Li-Ion |
Polymer
Li-ion |
| Voltage
(V) |
2 |
1.2 |
1.2 |
3.6 |
3.6 |
| Weight
energy density (Wh/Kg) |
35 |
50 |
80 |
125 |
170 |
| Volume
energy Density (Wh/l) |
80 |
150 |
200 |
320 |
400 |
|
Cycle
life (times) |
300 |
500 |
500 |
800 |
1000 |
| Selfdischarge
(%/ month) |
0 |
25-30 |
30-35 |
6-9 |
2-5 |
| Electrolyte
state |
Liquid |
Liquid |
Liquid |
Liquid |
Polymer
Gel |
| Min.
thickness |
>
10 mm |
>3mm |
>3mm |
>3mm |
<1mm |
| Memory
effect |
no |
yes |
yes |
No |
No |
| Pollution
|
yes |
yes |
No |
No |
No |
| Production
cost |
lowest |
Low |
middle |
High |
Middle |
| Advantages |
High
drain current and low cost |
Middle
drain current and low cost, smaller volume |
Middle
drain current and cost, higher capacity |
higher
capacity and lighter weight |
Highest
capacity, lighter weight and flexible shaple |
| Disadvantages |
Too
heavy |
Environmental
not friendly |
Higher
self-discharge and weight |
Low
drain current and higher cost |
Low
drain current and very high cost |
| Applications |
Car
and lighting |
Power
tool, cordless phone and emergency lighting etc. |
Toy,
PDA,, MP3 and digital camera etc |
Cellular
phone and laptop computer |
Labtop
computers |
top of page
Nickel/Cadmium Cells
Anode: Cadmium
Cathode: Nickel oxyhydroxide Ni(OH)2
Electrolyte: Aqueous potassium hydroxide
(KOH)
Applications: Calculators,
digital cameras, pagers, lap tops, tape recorders, flashlights,
medical devices (e.g., defibrillators), electric vehicles, space
applications
The anode is nickel-plated,
woven mesh, and the cathode is a cadmium-plated net. Since the
cadmium is just a coating, this cell's negative environmental
impact is often exaggerated. (Incidentally, cadmium is also
used in TV tubes, some semiconductors, and as an orange-yellow
dye for plastics.) The electrolyte, KOH, acts only as an ion
conductor and does not contribute significantly to the cell's
reaction. That's why not much electrolyte is needed, so this
keeps the weight down. (NaOH is sometimes used as an electrolyte,
which doesn't conduct as well, but also doesn't tend to leak
out of the seal as much). Here are the cell reactions: |
| Reaction |
V vs SHE |
| Cd + 2OH- ?a> Cd(OH)2
+ 2e- |
0.81 |
| NiO2 + 2H2O
+ 2e- ?a> Ni(OH)2 + 2OH- |
0.49 |
| Cd +NiO2 + 2H2O
?a> Cd(OH)2 + Ni(OH)2 |
1.30 |
Advantages include good
performance in high-discharge and low-temperature applications.
They also have long shelf and use life. Disadvantages are
that they cost more than the lead-acid battery and have lower
power densities. Possibly its most well-known limitation is
a memory effect, where the cell retains the characteristics
of the previous cycle.
This term refers to a temporary
loss of cell capacity, which occurs when a cell is recharged
without being fully discharged. This can cause cadmium hydroxide
to passivate the electrode, or the battery to wear out. In
the former case, a few cycles of discharging and charging
the cell will help correct the problem, but may shorten the
lifetime of the battery. The true memory effect comes from
experience with a certain style of NiCad in space use, which
were cycled within a few percent of discharge each time.
An important thing to know
about "conditioning " a NiCd battery is that the deep discharge
spoken of is not a discharge to zero volts, but to about 1
volt per cell. top of page |
Nickel/Metal Hydride (NiMH)
Cells
Anode: Rare-earth or nickel alloys
with many metals
Cathode: Nickel oxyhydroxide
Electrolyte: Potassium hydroxide
Applications: Cellular phones, camcorders,
emergency backup lighting, power tools, laptops, portable, electric
vehicles
This sealed cell is a hybrid
of the NiCd and NiH2 cells. Previously, this battery
was not available for commercial use because, although hydrogen
has wonderful anodic qualities, it requires cell pressurization.
Fortunately, in the late 1960s scientists discovered that some
metal alloys (hydrides such as LiNi5 or ZrNi2)
could store hydrogen atoms, which then could participate in
reversible chemical reactions. In modern NiMH batteries, the
anode consists of many metals alloys, including V, Ti, Zr, Ni,
Cr, Co, and Fe.
Except for the anode, the NiMH
cell very closely resembles the NiCd cell in construction. Even
the voltage is virtually identical, at 1.2 volts, making the
cells interchangeable in many applications. Here are the cell
reactions: |
| Location |
Reactions |
Voltage |
| Anode |
MH + OH- ?a> M + H2O
+ e- |
0.83 |
| Cathode |
NiOOH + H2O + e- ?a>
Ni(OH)2 + OH- |
0.52 |
| Overall |
NiOOH + MH ?a> Ni(OH)2 + M |
1.35 |
The anodes used in these
cells are complex alloys containing many metals, such as an
alloy of V, Ti, Zr, Ni, Cr, Co, and (!) Fe. The underlying
chemistry of these alloys and reasons for superior performance
are not clearly understood, and the compositions are determined
by empirical testing methods.
A very interesting fact about
these alloys is that some metals absorb heat when absorbing
hydrogen, and some give off heat when absorbing hydrogen.
Both of these are bad for a battery, since we would like the
hydrogen to move easily in and out without any energy transfer.
The successful alloys are all mixtures of exothermic and endothermic
metals to achieve this. |
top of page
Industrial
Standard Cylindrical Battery Sizes
| Cell Size |
Diameter (mm) |
Length (mm) |
NiCad Weight(grams) |
NiMH Weight(grams) |
| A Size Batteries |
| AAAA |
8.4 |
40.2 |
10 |
10 |
| 4/3 AAAA |
8.4 |
67 |
12-13 |
13 |
| 1/4 AAA |
10.5 |
14 |
2.5-3.5 |
2.5-4 |
| 1/3 AAA |
10.5 |
16 |
5.5 |
5.5 |
| 1/2 AAA |
10.5 |
22 |
|
7 |
| 2/3 AAA |
10.5 |
30 |
6-8 |
8-9 |
| AAA36 |
10.5 |
36 |
|
11 |
| 4/5 AAA |
10.5 |
37 |
|
11 |
| AAA38 |
10.5 |
38 |
|
11 |
| 3/4 AAA |
10.5 |
39.5 |
12 |
12 |
| AAA42 |
10.5 |
42 |
|
12 |
| AAA |
10.5 |
44.5 |
10 |
13 |
| 5/4 AAA |
10.5 |
50 |
14 |
15 |
| L-AAA |
10.5 |
50 |
13 |
14 |
| 4/3 AAA |
10.5 |
67 |
17 |
18 |
| 5/3 AAA |
10.5 |
67 |
19 |
19 |
| LL-AAA |
10.5 |
67 |
17 |
18 |
| 3/2 AAA |
10.5 |
67 |
19 |
20 |
| 6/4 AAA |
10.5 |
67 |
20 |
20 |
| 7/5 AAA |
10.5 |
66.5 |
15 |
15 |
| 7/4 AAA |
10.5 |
76 |
19 |
20-21 |
| 7/3 AAA |
10.5 |
80 |
|
23 |
| SL AAA |
10.5 |
80 |
|
23 |
| 1/3 AA |
14.2 |
17.5 |
6.5 |
7 |
| 1/2 AA |
14.2 |
30 |
12 |
15 |
| 2/3 AA |
14.2 |
28.7 |
13-15 |
13-16 |
| 4/5 AA |
14.2 |
43 |
20 |
22 |
| AA |
14.2 |
50 |
21 |
27 |
| AA flat top |
14.2 |
48 |
21 |
27 |
| 5/4 AA |
14.2 |
64.5 |
|
29 |
| L-AA |
14.2 |
65 |
29 |
30 |
| 4/3 AA |
14.2 |
65.2 |
30 |
30 |
| 7/5 AA |
14.2 |
70 |
29 |
39 |
| 1/3 A |
17 |
21 |
|
|
| 1/2 A |
17 |
25 |
17 |
21 |
| 2/3 A |
17 |
28.5 |
18-20 |
20-23 |
| 4/5 A |
17 |
43 |
26-31 |
32-35 |
| A |
17 |
50 |
32 |
40 |
| 4/3 A |
17 |
67 |
50 |
55 |
| L-A |
17 |
67 |
48 |
53 |
| 7/5 A |
17 |
70 |
44.8 |
56 |
| Fat A |
18 |
50 |
38 |
42 |
| 4/3 Fat A |
18 |
67 |
56 |
60 |
| L-Fat A |
18 |
67 |
55 |
60 |
| Sub
C Size Batteries |
| 1/2 SC |
23 |
26 |
30 |
|
| 2/3 SC |
23 |
28 |
25 |
28 |
| 4/5 SC |
23 |
34 |
38 |
42 |
| SC (sub C) |
23 |
43 |
52 |
55 |
| 5/4 Sub C |
23 |
49.5 |
65-67 |
70 |
| 4/3 SC |
23 |
50 |
60 |
66 |
| L-SC |
23 |
50 |
57 |
63 |
| C
Size Batteries |
| 1/2 C |
26 |
24 |
31 |
34 |
| 3/5 C |
26 |
30 |
40 |
44 |
| 2/3 C |
26 |
31 |
45 |
50 |
| C |
26 |
46 |
72 |
80 |
| 5/4 C |
26 |
58 |
90 |
100 |
| D
Size Batteries |
| 1/2 D |
33 |
37 |
81-84 |
81 |
| 2/3 D |
33 |
43.4 |
98-105 |
115 |
| D |
33 |
58 |
105-145 |
105-160 |
| 4/3 D |
33 |
89 |
140-190 |
175 |
| 3/2 D |
33 |
90.3 |
195-236 |
240 |
| F
Size Batteries |
| F |
33 |
91.2 |
231 |
255 |
| SF (super F) |
41.4 |
89.1 |
393 |
425 |
- Diameter & Length can vary as much as
0.1mm~1 mm between different manufacturers
- Weight of a cell depends on manufacturer
The purpose of the weight column is to give a feel for how
heavy a cell will be. Your results may vary.
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|
This Table is the intellectual property of our affiliate vendor, BatterySpace.com
(copyright 2004) |