UltraBattery

Research conducted by independent laboratories, such as the United States's Sandia National Laboratories,[1] the Advanced Lead-Acid Battery Consortium (ALABC),[2] the Commonwealth Scientific and Industrial Research Organisation (CSIRO)[3] and commercial tests by East Penn Manufacturing, Furukawa Battery and Ecoult indicate that in comparison with conventional valve regulated lead acid (VRLA) batteries, UltraBattery technology has higher energy efficiencies, a longer lifetime and superior charge acceptance under partial state of charge (SoC) conditions.

In 2007, East Penn Manufacturing obtained a global head license to manufacture and commercialize UltraBattery technology for motive and automotive applications (in various territories) and for stationary energy storage applications (globally, outside Japan and Thailand, where Furukawa Battery is the head license holder).

During normal lead–acid battery operation, lead sulfate crystals grow on the negative electrode during discharging and dissolve again during charging.

This is particularly the case when the battery is forced to perform at very high rates of discharge, which tends to promote lead sulfate crystal growth on the surface of the electrode.

Hence the reaction is favored toward the outer wall of the electrode, where crystals may form in a dense mat, rather than in dispersed clumps throughout the plate.

“Hard” sulfation is generally irreversible since the side reactions tend to dominate as more and more energy is pushed into the battery.

[11] To reduce the likelihood of hard sulfation, conventional VRLA batteries should therefore be discharged at specific rates, determined by various charging algorithms.

Conventional VRLAs are somewhat constrained to operate in the inefficient region toward the top of their charge capacity in order to protect them against damage by sulfation.

Hund et al., for instance, found that typical VRLA battery failure modes (water loss, negative plate sulfation, and grid corrosion) are all minimized in the UltraBattery.

Hund's results also showed that the UltraBattery, used in a high rate partial state of charge application, exhibits reduced gassing, minimized negative plate hard sulfation, enhanced power performance and minimized operating temperature compared with conventional VRLA cells.

[2] Laboratory results of UltraBattery prototypes show that their capacity, power, available energy, cold cranking and self-discharge meets, or exceeds, all performance targets set for minimum and maximum power-assist hybrid electric vehicles.

UltraBattery can be used to smooth and shift (i.e. store for later use) renewable energy sources on microgrids to improve predictable power availability.

Standalone microgrid systems combine diesel or other fossil fuels with UltraBattery storage to improve the efficiency of fossil-fuel energy generation.

Including energy storage in the system reduces the size of the gen-set (i.e. array of generators) because the batteries can handle peaks in the load.

An example of this type of microgrid is the King Island Renewable Energy Integration Project (KIREIP),[14] being undertaken by Hydro Tasmania.

This megawatt-scale renewable energy project aims to reduce both the cost of delivering power to the island and carbon pollution.

Another example of a community application is a 300 kW smart grid demonstration system set up by Furukawa Battery in the Maeda Area in Kitakyushu, Japan.

UltraBattery can manage variability on electricity grids in five main ways: frequency regulation, renewable energy integration (smoothing and shifting), spinning reserve, ramp-rate control, and power quality and weak-grid support.

UltraBattery can absorb and deliver power to the grid to help manage the balance between supply and demand, and to maintain consistent voltage.

Ecoult implemented a grid-scale energy storage system which provides 3 MW of regulation services on the grid of Pennsylvania-Jersey-Maryland (PJM) Interconnection in the United States.

The PNM Prosperity project features one of the United States’ largest combinations of photovoltaic energy and solar panel battery storage.

Many small-scale deployments of rooftop photovoltaic panels tend to multiply the effect of the intermittency of solar generation – creating a problem for grid operators.

[5] CSIRO, claims “The UltraBattery is about 70 per cent cheaper to make than batteries with comparable performance and can be made using existing manufacturing facilities”.

[5] In automotive applications in a hybrid electric vehicle, UltraBatteries can be operated more or less continuously in a partial SoC regime without being refreshed.

However the presence of UltraBattery's parallel ultracapacitor apparently protects the negative terminal from the large surface preponderance of lead sulfate crystals that affects VRLA batteries operated at high rates of discharge or for long periods in pSoC operation, increasing the rechargeability of the cell (see also Hard Sulfation).

Tests have been conducted by independent laboratories, as well as by East Penn Manufacturing, Furukawa and Ecoult, to compare the performance of UltraBattery with conventional VRLA batteries.

[4] The Advanced Lead Acid Battery Consortium (ALABC) tested the durability of UltraBattery in the high-rate, partial state-of-charge operation of a Honda Civic hybrid electric vehicle.

[2] Under micro, mild and full hybrid electric vehicle duties, the cycling performance of the UltraBattery was at least four times longer than conventional state-of-the-art VRLA batteries and was comparable or even better than that of Ni-MH cells.

Tests by Sandia National Laboratories show that UltraBattery performs for much longer than conventional VRLA batteries in utility cycling.

In the same test an UltraBattery manufactured by East Penn ran for more than 22,000 cycles, maintaining essentially 100% of its initial capacity without having been supplied a recovery charge.