having an atomic structure that is not periodic.
measure of cell capacity. Product of current
in amperes multiplied by the discharge time.
an electrode where an oxidation reaction occurs.
The negative electrode is the anode on discharge, the
positive is on charge.
one or more cells connected to form one unit
and having provisions for external connections.
The system level form of a battery. Often includes:
battery modules, mechanical housing, electronics, and
the rated amount of energy stored in the cell
(battery), normally measured in ampere-hours (Ah).
an electrode where a reduction reaction occurs.
The positive electrode is the cathode on discharge and
the negative is the cathode on charge.
an electrochemical device capable of the interconvertion
of electrical and chemical energy. Electrochemical cells
include battery cells, fuel cells, and electrolyzer
the nominal individual cell voltage.
the process in which more energy is removed
from a battery than is restored.
the process where the total average energy removed
and restored to a battery is zero.
having a repeating atomic structure in all three
the number of times a battery can be charged
and discharged. This is dependent upon the conditions
such as the state-of-charge limits and the charge and
discharge rates. Electric vehicle (EV) applications
typically require a cycle life of over 1000 deep cycles.
Hybrid electric vehicle (HEV) applications require a
cycle life of over 100,000 shallow cycles.
the percentage of the battery capacity that
is discharged (100%- SOC.)
minimizing and lifting of lattice constraints,
which provides new degrees of freedom, permitting the
placement of elements in multi-dimensional spaces where
they interact in ways not previously available. This
allows the use of multi-elements and complex materials
where positional, translational, and compositional disorder
remove restrictions so that new local order environments
can be generated controlling the physical, electronic,
and chemical properties of the material, thereby permitting
the synthesis of new materials with new mechanisms.
a chemical reactor containing reactive and electrically
conductive materials which react in a controlled manner
to produce direct current electricity.
component of the battery that stores chemical
energy on charge and generates electrical energy on
discharge. Contains charge storage materials, nickel
hydroxide in the positive electrode and metal hydride
in the negative electrode for a nickel-metal hydride
battery. Also, contains electronically conducting substrate
for electrical path to battery terminals.
serves as the path for completing the electrical
circuit inside of the cell via the transport of ions
from one electrode to the other.
the amount of energy stored in a specific volume
or weight. Usually, this refers to the volumetric energy
density measured in Wh/L. However, this can also refer
to the gravimetric energy density, which is the same
thing as specific energy in Wh/kg.
a vehicle propelled exclusively by an electric
drive system powered by an electrochemical energy storage
device, typically a rechargeable battery.
an electric vehicle that derives its electricity
from a fuel cell.
a vehicle that is propelled both by a fuel cell
and an electrochemical energy storage device coupled
to an electric drive.
charging a battery at a fixed or temperature-compensated
voltage to maintain state of charge (SOC).
measure of how much energy can be stored in
the battery per unit weight (Watt hours per kilogram
a vehicle that is propelled both by an electrochemical
energy storage device coupled to an electric drive and
an auxiliary power unit power by a conventional fuel,
such as reformulated gasoline, direct injection diesel,
compressed natural gas, or hydrogen.
effects seen by shallow discharges of a battery.
Typically a problem with NiCd batteries and not demonstrated
in NiMH batteries.
battery consisting of one or more nickel electrode,
which utilizes nickel hydroxide as an active material,
and one or more metal hydride electrodes, which utilize
metal hydride as an active material. This battery —
developed by Energy Conversion Devices, Inc. (ECD Ovonics)
over the past 25 years — is a high-energy, high-power
battery with excellent life characteristics and excellent
environmental attributes. It has a nominal voltage of
the energy available from a battery usually
in Wh, delivered at a standard constant current discharge
condition, such as C/3 (current needed to provide complete
discharge in 3 hours).
approximate voltage of battery under load or
under typical discharge conditions, normally rounded
off to an even number. Nickel metal hydride (NiHM) batteries
have a nominal voltage of 1.2V/cell.
[after S.R. Ov(shinsky) + (electr)onic] - the
term used to describe our proprietary materials, products,
interconnecting cells or batteries by joining
negative terminals together and separately joining positive
terminals together. The parallel cells or batteries
have the same voltage as the individual units; however,
the capacity is the sum of the capacities of the individual
the maximum amount of power available for a
sustained period of time, typically 10 to 30 seconds
under specified conditions of voltage limits. Typically,
the USABC has specified that it is the power that can
be delivered above 2/3 of the open circuit voltage for
the effect of discharge current on the stored
energy available for discharge. In contrast to the undesirably
large Peukert effect for lead-acid batteries, Ovonic
NiMH batteries have a minimal Peukert effect.
a non-rechargeable battery that can be discharged
only once; single use.
the peak power available from a specific volume
or weight. Usually, this refers to the volumetric power
density measured in W/L.
the amount of power that can be drawn from each
cell at the end of discharge voltage (watts per cell(W/cell)).
This is a function of cell capacity, impedance, and
end of discharge voltage.
the charge power applied to the battery during
the recovery of kinetic energy from electric and hybrid
vehicles. Electric propulsion vehicles can generate
energy during braking by turning the motor backwards
so it operates as a generator.
a rechargeable battery, such as the Ovonic NiMH
the loss of available battery capacity on stand,
due to chemical side-reactions at battery electrodes.
provides physical isolation between the electrodes
to prevent shorting and to separate the electrode reactions
from one another. It also must be able to pass ions
through its structure to allow for current flow.
interconnecting cells or batteries by connecting
the positive terminal of one unit to the negative terminal
of the next in sequence. The series cells or batteries
have the same capacity as the individual units; however,
the voltage is the sum of voltages of the individual
the amount of energy capacity divided by the
weight or volume of the battery, usually measured in
the peak power available from a specific weight,
usually measured in W/kg.
the amount of charge available for discharge
from a battery in comparison to the rated capacity,
usually given in percent.
United States Advanced Battery Consortium.
fundamental electrical concept, the electrical
potential given in volts (V). Electricity will flow
through conductors proportionally to the difference
measure of how much energy can be stored in
the battery per unit volume (watt hours per liter (Wh/L)).
a measurement of energy that a battery is capable
of producing. This measurement is calculated by the
product of watts (power) times a time period. Unit of
electrical energy typically used to rate batteries.
watts per cell.
watts per kilogram.
watt hours per kilogram.
watt hours per liter.