raymond723
Jul 13, 09, 00:36
Lead-acid batteries are used in gasoline-driven automobiles and in electric and hybrid vehicles. They have the best discharge rate of secondary battery technology, they are the cheapest to produce, and they are rechargeable. The chemical reactions are:
Cathode (+):
Anode (−):
The positive electrode is made of lead dioxide (PbO2) and is reduced to lead sulfate (PbSO4), while sponge metallic lead (Pb) is oxidized to lead sulfate at the negative electrode. The electrolyte is sulfuric acid (H2SO4), which provides the sulfate ion (SO42−) for the discharge reactions.
The nickel-cadmium battery (Ni-Cd) is the most common battery used in communication satellites, in Earth orbiters, and in space probes. The chemical reactions are:
Cathode (+):
Anode (−):
Nickel hydroxide, NiO(OH), is the active cathode material, cadmium, Cd, is the active anode material, and aqueous potassium hydroxide, KOH, is the electrolyte.
There is considerable interest in the development of nickel-metal hybrid (Ni/MH) batteries for electric and hybrid vehicles. These batteries operate in concentrated KOH electrolyte. The electrode reactions are:
Cathode (+):
Anode (−):
Ni/MH batteries use nickel hydoxide, NiO(OH), as the active material for the cathode, a metal hydride, MH, as the anode, and a potassium hydroxide, KOH, solution as the electrolyte. The metal hydride is a type of alloy (hydrogen absorption alloy) that is capable of undergoing a reversible hydrogen absorbing-desorbing process while the battery is discharged and charged. Current research is directed at improving the performance of the metal hydride anode and making the battery rechargeable.
Lithium ion (Li-ion) batteries are environmentally friendly batteries that offer more energy in smaller, lighter packages and thus are promising candidates for electric and hybrid vehicle applications. The electrode reactions are:
Cathode (+):
Anode (−):
Li-ion batteries use various forms of carbon (C) as anode material because carbon can reversibly accept and donate significant amounts of lithium (as LixC6. Li-intercalation compounds (such as LiCoO2, LiMn2O4, and LiNiO2) are used as cathode materials. Electrolyte mixtures include a lithiated salt (LiPF6 or LiClO4) dissolved into a nonaqueous solvent (ethylene carbonate, propylene carbonate, or dimethyl carbonate). Because Li is a highly reactive metal in aqueous solution, Li-ion batteries are constructed to keep Li in its ionic state, and nonaqueous solvents are used. The next step in lithium-ion battery technology is believed to be the lithium polymer battery, in which a gelled or solid electrolyte will replace the liquid electrolyte.
Cathode (+):
Anode (−):
The positive electrode is made of lead dioxide (PbO2) and is reduced to lead sulfate (PbSO4), while sponge metallic lead (Pb) is oxidized to lead sulfate at the negative electrode. The electrolyte is sulfuric acid (H2SO4), which provides the sulfate ion (SO42−) for the discharge reactions.
The nickel-cadmium battery (Ni-Cd) is the most common battery used in communication satellites, in Earth orbiters, and in space probes. The chemical reactions are:
Cathode (+):
Anode (−):
Nickel hydroxide, NiO(OH), is the active cathode material, cadmium, Cd, is the active anode material, and aqueous potassium hydroxide, KOH, is the electrolyte.
There is considerable interest in the development of nickel-metal hybrid (Ni/MH) batteries for electric and hybrid vehicles. These batteries operate in concentrated KOH electrolyte. The electrode reactions are:
Cathode (+):
Anode (−):
Ni/MH batteries use nickel hydoxide, NiO(OH), as the active material for the cathode, a metal hydride, MH, as the anode, and a potassium hydroxide, KOH, solution as the electrolyte. The metal hydride is a type of alloy (hydrogen absorption alloy) that is capable of undergoing a reversible hydrogen absorbing-desorbing process while the battery is discharged and charged. Current research is directed at improving the performance of the metal hydride anode and making the battery rechargeable.
Lithium ion (Li-ion) batteries are environmentally friendly batteries that offer more energy in smaller, lighter packages and thus are promising candidates for electric and hybrid vehicle applications. The electrode reactions are:
Cathode (+):
Anode (−):
Li-ion batteries use various forms of carbon (C) as anode material because carbon can reversibly accept and donate significant amounts of lithium (as LixC6. Li-intercalation compounds (such as LiCoO2, LiMn2O4, and LiNiO2) are used as cathode materials. Electrolyte mixtures include a lithiated salt (LiPF6 or LiClO4) dissolved into a nonaqueous solvent (ethylene carbonate, propylene carbonate, or dimethyl carbonate). Because Li is a highly reactive metal in aqueous solution, Li-ion batteries are constructed to keep Li in its ionic state, and nonaqueous solvents are used. The next step in lithium-ion battery technology is believed to be the lithium polymer battery, in which a gelled or solid electrolyte will replace the liquid electrolyte.