How we stand against other battery technologies:
Characteristics of Existing Battery Technologies.
1. Nickel-Cadmium batteries have low energy density of 40 Wh/kg, do not survive required numbers of cycles, have the "memory effect."
2. Widely utilized lead acid batteries have an advantage - low cost, but low power density and energy, do not survive many cycles at 100% discharge.
3. NiMH: batteries have a specific energy of 80 Wh/kg but not enough power. The increased max power density up to 1 kW/kg (in hybrid cars) is achieved by specific energy loss up to 34 Wh/kg. Besides the metal hybrid batteries have a high self-discharge during extended storage, and irreversibly lose the capacity during deep discharge.
Despite successes achieved in the production of high-power batteries for hybrid cars (usually metal - hydride), the principle processes in electrodes and battery design have changed little: a special powder with a high degree of development on the surface—combined with some binding additives—is smeared or pressed on the substrate. Such electrodes have a number of significant disadvantages, including:
· powder materials have a limited degree of development on the conducting surface;
· the powder particles limit the discharging and charging currents;
· the presence of binding materials facilitates gassing problems ; and
· the presence of various additives in active mass added in order to improve electrical conductivity and adhesion of particles creates problems with disposing and recycling of the batteries.
Promised advances in design and production methods of HEV batteries based on the conventional method of electrodes production has not produced significant cost or size reduction of the batteries.
Li-ion: Recent battery troubles on the Boeing 787 show that the market still lacks an ideal, safe battery. The Li-ion safety records, costs (justified only for small electronic applications), safe disposal, complicated recycling procedures, potential risks, special protection/control overhead/charger, lack of high power capacity, and failure to operate in low temperatures leaves the market open for better alternatives.
Characteristics of Ni-Co Battery Technology
Nickel-Cobalt Batteries is based on nanoporous electrochemical growth of active conductive mass on nickel, titanium or iron substrate.
This technology has the advantage over classical powder technology used in conventional battery production: in conventional powder technology there is a need to use some powders bonding materials, which must be electron-conductive, which leads to a reduction of the specific characteristics of the electrodes and the cell.
The Nickel-Cobalt battery characteristics are superior to all batteries other than rechargeable lithium-ion, and for the price, safety, and simplicity of utilization - are superior to lithium ion batteries
The first tests on the models showed high performance and capacity. Maximum power density of 4.5 kW/kg. When the discharge power is 1.5 kW/kg, the battery can give 50% of its energy; at the discharge power of 1 kW/kg the battery can provide up to 65% of its energy.
The distinctive feature of the negative cobalt electrode battery model:
- · Almost 100% reversibility in cycling;
- · Lack of hydrogen to a full charge,
- · Flat discharge voltage plateau (horizontal curve of the charge/discharge by 5C).
- · The hysteresis between charge and discharge curves at current 5C is 50-80 mV,
- · The potential of hydrogen evolution on the electrode is 250 mV more negative than the potential of charge, which means that the high over-voltage of hydrogen evolution provides a reversible electrode cycling without hydrogen.
- · The is no gas in pores, therefore discharging can immediately follow charging without waiting for the recombination of gas (not increase in resistance in the pores).
- · Discharge and charge curves coincide with great accuracy in battery cycles.
- · Besides, the negative electrode has virtually no self-discharge (self-discharge of a nickel-cobalt battery is due to positive electrode, which is 100% restored during recharging.)
- · Operates at low and high temperature.