Li-ion batteries

1
Li-ion batteries

• Positive electrode Lithiated form of a
  transition metal oxide (lithium cobalt
  oxide-LiCoO2 or lithium manganese oxide LiMn2O4)
• Negative electrode Carbon (C),
• usually graphite (C6)
• Electrolyte solid lithium-salt electrolytes
• (LiPF6, LiBF4, or LiClO4)
• and organic solvents (ether)

discharge
http//www.fer.hr/_download/repository/Li-ION.pdf
2
Li-ion batteries

• Chemical reaction (discharge)
• Positive electrode
• Negative electrode
• Overall
• In the above reaction x can be 1 or 0
• With discharge the Co is oxidized from Co3 to
  Co4. The reverse process (reduction) occurs when
  the battery is being charged.

LiCoO2
Li1-xCoO2 xLi xe-
Through electrolyte
Through load
xLi xe- 6C LixC6
LiCoO2 C6
Li1-xCoO2 C6Lx
3
Li-ion batteries

• Contrary to lead-acid batteries, Li-ion
  batteries do not accept well a high initial
  charging current.
• In addition, cells in a battery stack needs to
  be equalized to avoid falling below the minimum
  cell voltage of about 2.85 V/cell.
• Thus, Li-ion batteries need to be charged at
  least initially with a constant-current profile.
  Hence they need a charger
• Typical float voltage is above 4 V
• (typically 4.2 V).

Advanced Lithium Ion Battery Charger V.L.
Teofilo, L.V. Merritt and R.P. Hollandsworth
Saft Intensium 3 Li-ion battery
4
Li-ion batteries

• Effects of temperature

http//www.gpbatteries.com/html/pdf/Li-ion_handboo
k.pdf
5
Li-ion batteries

• Controlled charging has 2 purposes
• Limiting the current
• Equalizing cells

Increased Performance of Battery Packs by Active
Equalization Jonathan W. Kimball, Brian T. Kuhn
and Philip T. Krein
Advanced Lithium Ion Battery Charger V.L.
Teofilo, L.V. Merritt and R.P. Hollandsworth
Saft Intensium 3 Li-ion battery
6
Li-ion batteries

• Factors affecting life
• Charging voltage.
• Temperature
• Age (time since manufacturing)
• Degradation process oxidation

7
Li-ion batteries

• Advantages with respect to lead-acid batteries
• Less sensitive to high temperatures (specially
  with solid electrolytes)
• Lighter (compare Li and C with Pb)
• They do not have deposits every charge/discharge
  cycle (thats why the efficiency is 99)
• Less cells in series are need to achieve some
  given voltage.
• Disadvantages
• Cost

8
Ni-MH batteries

• Negative electrode Metal Hydride such as AB2
  (Atitanium and/or vanadium, B zirconium or
  nickel, modified with chromium, cobalt, iron,
  and/or manganese) or AB5 (Arare earth mixture of
  lanthanum, cerium, neodymium, praseodymium,
  Bnickel, cobalt, manganese, and/or aluminum)
• Positive electrode nickel oxyhydroxide
  (NiO(OH))
• Electrolyte Potassium hydroxide (KOH)

Cobasys batteries
9
Ni-MH batteries

• Chemical reaction (discharge)
• Positive electrode
• Negative electrode
• Overall
• The electrolyte is not affected because it does
  not participate in the reaction.

NiO(OH) H2O e- Ni(OH)2
OH-
Through electrolyte
Through load
MH OH- M H2O
e-
NiO(OH) MH
Ni(OH)2 M
10
Ni-MH batteries

• It is not advisable to charge Ni-MH batteries
  with a constant-voltage method. Ni-MH batteries
  do not accept well a high initial charging
  current.
• Float voltage is about 1.4 V
• Minimum voltage is about 1 V.

Cobasys Nigen battery
Saft NHE module battery
11
Ni-MH batteries

• Effects of temperature

Saft NHE module battery
http//www.panasonic.com/industrial/battery/oem/im
ages/pdf/panasonic_nimh_overview.pdf
12
Ni-MH batteries

• Advantages
• Less sensitive to high temperatures than Li-ion
  and Lead-acid
• Handle abuse (overcharge or over-discharge
  better than Li-ion bat
• Disadvantages
• More cells in series are need to achieve some
  given voltage.
• Cost

13
Ni-Cd batteries

• Negative electrode Cadmium (Cd) instead of
  the MH in Ni-MH batteries
• Positive electrode nickel oxyhydroxide
  (NiO(OH)) the same than in Ni-MH
• batteries
• Electrolyte Potassium hydroxide
• (KOH) solution

Saft batteries
14
Ni-Cd batteries

• Chemical reaction (discharge)
• Positive electrode
• Negative electrode
• Overall
• The electrolyte is not affected because it does
  not participate in the reaction.

2NiO(OH) 2H2O 2e-
2Ni(OH)2 2OH-
Through electrolyte
Through load
Cd 2OH- Cd(OH)2
2e-
2NiO(OH) Cd 2H2O
2Ni(OH)2 Cd(OH)2
15
Ni-Cd batteries

• It is not advisable to charge Ni-Cd batteries
  with a constant-voltage method. Ni-Cd batteries
  do not accept well a high initial charging
  current, but they can withstand it sporadically.
• Float voltage is about 1.4 V
• Minimum voltage is about 1 V.

Saft Ultima plus
http//www.saftbatteries.com/doc/Documents/telecom
/Cube788/tel_tm_en_0704.26962445-6b1b-44fb-aea7-42
834c32be40.pdf
16
Ni-Cd batteries

• Effects of temperature

http//www.saftbatteries.com/doc/Documents/telecom
/Cube788/tel_tm_en_0704.26962445-6b1b-44fb-aea7-42
834c32be40.pdf
17
Ni-Cd batteries

• Due to their better performance at high
  temperatures, Ni-Cd batteries are replacing
  Lead-acid batteries in outdoor stationary
  applications. But, they do not resist hurricanes
  very well, yet(ATTs DLC at Sabine Pass CO,
  Saft NCX batteries)

18
Ni-Cd batteries

• Advantages
• Less sensitive to high temperatures than all the
  other batteries
• Handle some abuse (overcharge or over-discharge
  better than Li-ion bat)
• Disadvantages
• More cells in series are need to achieve some
  given voltage.
• Cost

19
Ni-Cd batteries

• Comparison with Ni-MH batteries (not much of a
  difference)

Portable NiCd- and Ni-MH-Batteries for Teiecom
Applications J. Heydecke and H.A. Kiehne
20
Battery technologies
Cobasys Inside the Nickel Metal Hydride Battery