Nickel Battery Technologies
Nickel battery technologies have revolutionized the way we store and use energy, offering a range of solutions for various applications. From the early days of nickel-cadmium (NiCd) batteries to the more advanced nickel-metal hydride (NiMH) and nickel-hydrogen (NiH2) variants, these technologies have continually evolved to meet the growing demands for efficient, reliable, and environmentally friendly energy storage.
Each type of nickel battery brings its unique advantages and challenges, shaping their roles in consumer electronics, hybrid vehicles, and even space exploration. This article explores the development, features, and applications of nickel battery technologies, highlighting their impact on modern energy storage solutions.
What batteries are made with nickel?
Batteries made with nickel include Nickel Cadmium (NiCd) batteries, Nickel Hydrogen (NiH2) batteries, and Nickel Metal Hydride (NiMH) batteries. A common feature among these batteries is that their positive electrode is made of nickel oxyhydroxide (NiOOH).
Are nickel batteries better than lithium?
Lithium-ion batteries usually have twice the energy density of standard nickel-cadmium batteries. They also have the potential for even higher energy densities. Their load characteristics are quite good, performing similarly to nickel-cadmium batteries during discharge.
Nickel-Cadmium Battery
Waldemar Jungner of Sweden invented the first Ni-Cd battery in 1899. Back then, its only rival was the lead acid battery, which was less durable both physically and chemically. With some minor improvements to the initial prototypes, the energy density of Ni-Cd batteries quickly rose to about half that of primary batteries, and significantly higher than that of lead-acid batteries.
What is the chemical reaction of the NiCd battery?
The chemical reaction of a NiCd battery involves the following components:
- Positive Electrode: Nickel Oxyhydroxide (NiOOH)
- Negative Electrode: Cadmium (Cd)
- Electrolyte: Alkaline electrolyte (potassium hydroxide)
At the positive electrode, the reaction is:
NiOOH+H2O+e−→Ni(OH)2+OH−
At the negative electrode, the reaction is:
Cd+2OH−→Cd(OH)2+2e−
The overall reaction is:
2NiOOH+Cd+2H2O<–> 2Ni(OH)2+Cd(OH)2
This reaction results in the formation of Nickel Hydroxide and Cadmium Hydroxide in the electrolyte, and the battery has a voltage of 1.35V.
What’s the theoretical specific capacity and energy of Ni-Cd battery?
The theoretical specific capacity and energy of a Ni-Cd battery can be calculated as follows:
- Overall Reaction:
2NiOOH+Cd+2H2O<–> 2Ni(OH)2+Cd(OH)2 - Relative Masses:
- NiOOH: 2x (58.7 + 16 + 16 + 1) = 2 x 91.7 = 183.4
- Cd: 112.4
- H2O: 2×18 = 36
- For the overall reaction, (2e–) are transferred.
- To generate a charge Q = 2 x1.602 x10-19 C, we need a mass M = 331.8 / (6.02 x1023) g of the battery.
- Specific Capacity:
Q/M = 161 Ah/kg - Specific Energy:
1.35V×161Ah/kg=217.4Wh/kg
Therefore, the theoretical specific capacity of a Ni-Cd battery is 161Ah/kg and the theoretical specific energy is 217.4Wh/kg.
Nickel-cadmium battery vs lead acid batteries
NiCd batteries have several advantages over lead acid batteries. One significant benefit is that NiCd batteries do not contain acid, which reduces electrolytic erosion and results in a longer lifespan. Additionally, NiCd batteries are more resistant to temperature extremes, making them suitable for a wider range of environments.
They also have a higher power density, allowing them to store more energy per unit of weight compared to lead acid batteries. However, if NiCd batteries are overcharged, a reaction occurs at the electrodes that produce hydrogen and oxygen gases, potentially leading to gas overpressure. Despite this, their overall durability and efficiency make them a superior choice for many applications.
If overcharged:
Positive Electrode: 4OH– → 2H2O +O2+4e–
Negative Electrode: 4H2O+4e–→2H2+4OH–
Therefore: 2H2O→2H2 +O2 (gas overpressure)
What kind of trouble can those gases create?
The accumulation of gas in NiCd batteries can create several issues:
- Chemical Reaction Interference: Gas accumulation on the electrode surface can act as a barrier to chemical reactions, reducing the battery’s efficiency and performance.
- Physical Damage: High gas pressure can damage the electrode, separator, and battery enclosure, potentially leading to battery failure.
- Maintenance Requirements: The high gas pressure must be released periodically, leading to the loss of electrolytes during venting. This necessitates routine maintenance to replace the lost electrolyte and ensure the battery continues to function properly.
Why are nickel-cadmium batteries banned?
NiCd batteries have been banned for consumer use because they contain highly toxic cadmium, making them extremely harmful to the environment. This is why it is crucial to recycle these batteries properly.
Nickel-Hydrogen Battery
A nickel-hydrogen (NiH2) battery is a rechargeable battery that uses nickel and hydrogen. It’s important to note that this is different from a nickel–metal hydride (NiMH) battery. NiH2 batteries use hydrogen in gaseous form, storing it in a pressurized cell at up to 1200 psi (82.7 bar). These batteries can be seen as hybrid batteries, combining elements of NiCd battery and fuel cell technologies by using pressurized hydrogen instead of a cadmium electrode.
What is the chemical reaction of the NiH2 battery?
The chemical reaction of a NiH2 battery involves the following components and reactions:
- Positive Electrode: Nickel Oxyhydroxide (NiOOH)
- Negative Electrode: Hydrogen gas (H2)
- Electrolyte: Alkaline electrolyte (potassium hydroxide)
When discharging:
- At the positive electrode:
NiOOH+H2O+e−→Ni(OH)2+OH− - At the negative electrode:
1/2H2+OH−→H2O+1e− - Overall reaction:
NiOOH+1/2H2→Ni(OH)2
The voltage of the NiH2 battery is 1.29V.
What’s the theoretical specific capacity and energy of NiH2 battery?
The theoretical specific capacity and energy of a NiH2 battery can be calculated as follows:
- Relative Masses:
- NiOOH: (58.7 + 16 + 16 + 1 = 91.7)
- 1/2H2: 1
- For the overall reaction, (1e^-) is transferred.
- To generate a charge (Q = 1 \times 1.602 \times 10^{-19}) C, we need a mass (M = \frac{92.7}{6.02 \times 10^{23}}) g of the battery.
- Specific Capacity:
Q/M=288Ah/kg - Energy Density:
1.29V×288Ah/kg=371Wh/kg
Therefore, the theoretical specific capacity of a NiH2 battery is 288Ah/kg and the theoretical energy density is 371Wh/kg.
What are the advantages of a nickel-hydrogen battery?
Nickel-hydrogen batteries offer several advantages, including high gravimetric energy density, making them lightweight and efficient for energy storage. They have a high cycle life of up to 50,000 cycles and a calendar life of 15 years, ensuring long-term reliability. These batteries can be deeply discharged without damage and are tolerant to abuse, enhancing their durability. Additionally, they are maintenance-free, providing convenience for users. During charging, hydrogen is generated, and during discharging, it is absorbed, allowing gas pressure to serve as a simple measure of the state of charge (SOC).
How long will a nickel-hydrogen battery last?
Compared to other rechargeable batteries, a nickel-hydrogen battery offers a good specific energy of 55-60 watt-hours per kilogram, an exceptionally long cycle life of 40,000 cycles at 40% depth of discharge (DOD), and an operating life exceeding 15 years in satellite applications.
What are the disadvantages of a nickel-hydrogen battery?
Nickel-hydrogen batteries have several disadvantages, including low volumetric energy density due to the presence of gaseous hydrogen. They also have a high self-discharge rate and require high-pressure storage materials, which can complicate their design and handling. Additionally, their high cost limits their applications, making them less suitable for widespread use than other battery types.
What is a nickel-hydrogen battery application?
Nickel-hydrogen batteries are primarily used in non-civilian applications such as space probes and satellites. Notably, they are used to power the Hubble Space Telescope, benefiting from their long cycle life and reliability in the harsh environment of space.
Nickel-Metal Hydride (NiMH) Battery
Nickel-metal hydride (NiMH) batteries have rapidly gained acceptance since their first commercial availability in 1989. These batteries feature a well-developed positive electrode, utilizing nickel oxyhydroxide (NiOOH), which has been in use for over a century in Ni-Fe and Ni-Cd batteries. The negative electrode is based on hydrogen storage alloy developments, linking it to the hydrogen gas standard electrode potential reference. This combination of established and innovative technologies has contributed to the widespread adoption and reliability of NiMH batteries.
Example of Nickel-Metal-Hydride Battery
Is nickel metal hydride safe?
NiMH batteries are classified as non-dangerous goods. They are packaged in a way that effectively prevents both short circuits and movement that could cause short circuits.
What is the chemical reaction of the NiMH battery?
- Positive Electrode: NiOOH+H2O+𝑒−→Ni(OH)2+OH−
- Negative Electrode: MH+OH−→M+H2O+𝑒−
- Overall Reaction: NiOOH+MH⇌Ni(OH)2+M
This reaction produces an electromotive force (EMF) of 1.28V.
Calculate O.C.V. for a NiMH battery cell
To calculate the Open Circuit Voltage (O.C.V.) for a NiMH battery cell, we use the formula:
[ \text{O.C.V.} = V_{\text{positive electrode}} – V_{\text{negative electrode}} ]
Given:
- Positive electrode: NiOOH Vpositive electrode=+0.45 V
- Negative electrode: AB5+hydrogen Vnegative electrode=−0.83 V
Substitute the values into the formula:
O.C.V.=+0.45V−(−0.83V)
O.C.V.=+0.45V+0.83V
O.C.V.=1.28V
Therefore, the Open Circuit Voltage for a NiMH battery cell is 1.28 V.
Pros and cons of Ni-MH batteries
Nickel-metal hydride (NiMH) batteries offer several advantages. They have a high cycle life with high power output, making them durable and suitable for demanding applications. These batteries can operate at low temperatures, unlike some other types of batteries, which are beneficial in various environments. NiMH batteries are also environmentally friendly, as they do not contain toxic materials. Additionally, they have a high specific heat due to their aqueous electrolyte, which helps in managing heat generation during use. NiMH batteries are also tolerant of some operational abuse, further enhancing their durability.
However, NiMH batteries also have some disadvantages. They have a low specific energy storage capacity, typically below 1000 Wh/kg, which limits their use in applications requiring high energy density. NiMH batteries also tend to have a higher cost per unit of energy compared to other battery types, primarily due to the cost of nickel and other materials used in their construction. Another drawback is their poor charging efficiency at high temperatures, leading to inefficiencies and increased heat generation during charging.
Major comparative features of Nickel-Metal Hydride (NiMH) batteries
Nickel-metal hydride (NiMH) batteries boast several major comparative features. Firstly, they offer a long cycling life, making them durable and reliable for various applications. While they exhibit some hysteresis (memory effects) similar to Ni-Cd batteries, it is not as pronounced. Additionally, NiMH batteries have undergone improvements to minimize self-discharge rates, ensuring they retain their charge over extended periods of disuse. Moreover, NiMH batteries are produced on a mass scale for use in hybrid-electric vehicles (HEVs), highlighting their versatility and suitability for modern automotive applications.
Toyota Prius Battery Pack Overview
The Toyota Prius Battery Pack is a key component of the hybrid vehicle’s power system, providing the necessary energy for propulsion and auxiliary functions. It consists of 28 Panasonic prismatic nickel metal hydride modules, each containing six 1.2-volt cells, connected in series to produce a nominal voltage of 201.6 volts. In total, the battery pack comprises 168 individual cells. Despite its large capacity, the battery pack is relatively lightweight, weighing in at 53.3 kg. The pack boasts a discharge power capability of 20 kW at 50 percent state-of-charge, enabling efficient energy delivery to the vehicle’s electric motor.
Toyota Highlander Hybrid Battery Pack Overview
The Toyota Highlander Hybrid Battery Pack is a compact yet powerful energy storage system designed to enhance the performance of the hybrid SUV. It comprises 240 cells that can deliver a high voltage of 288 volts, providing ample power for the vehicle’s electric motor. Remarkably, despite its smaller size compared to the Prius battery pack, the Highlander Hybrid Battery Pack offers 40 percent more power. This demonstrates significant advancements in battery technology, allowing for improved efficiency and performance in a smaller footprint.
Why has Toyota chosen to utilize nickel metal hydride?
Toyota uses nickel metal hydride (NiMH) batteries because they offer a cost advantage compared to lithium-ion chemistry. NiMH battery packs, which Toyota first introduced in the 1997 Toyota Prius HEV in Japan, also provide the power needed to assist the Toyota Hybrid System, thereby boosting fuel economy.
Ford Escape Hybrid Battery Pack Overview
The Ford Escape Hybrid Battery Pack is a sophisticated energy storage system that powers the hybrid SUV’s electric motor. It comprises 250 Sanyo cells, each housed in a durable stainless steel case and rated at 1.3 volts. These cells are meticulously welded and wrapped together in groups of five to form a module, resulting in a total of 50 modules in the battery pack. The collective effort of these modules yields a high total voltage of 330 volts, ensuring ample power delivery to the vehicle’s electric drive system. This advanced battery pack design exemplifies Ford’s commitment to innovative hybrid technology in the Escape Hybrid.
Honda Insight Battery Pack Overview
The Honda Insight Battery Pack is a crucial component of the hybrid vehicle’s power system, providing the necessary energy for propulsion and auxiliary functions. It comprises 120 Panasonic 1.2-volt nickel metal hydride D cells, each capable of 100A discharge and 50A charge rates. These cells are carefully arranged and connected to deliver a total battery pack output of 144 volts, ensuring sufficient power for the vehicle’s electric motor. The Insight’s battery pack demonstrates Honda’s commitment to efficient and reliable hybrid technology, delivering a balance of performance and economy.
Conclusion
In conclusion, nickel battery technologies have significantly impacted various sectors by providing robust and versatile energy storage solutions. The evolution from nickel-cadmium (NiCd) to nickel-metal hydride (NiMH) and nickel-hydrogen (NiH2) batteries showcases continuous advancements in efficiency, capacity, and environmental sustainability.
These batteries have found applications in everything from consumer electronics to hybrid vehicles and space exploration, demonstrating their wide-reaching utility. As the demand for sustainable and reliable energy sources continues to grow, nickel battery technologies will undoubtedly play a crucial role in meeting these needs, driving innovation, and shaping the future of energy storage.
