IEEE Electrification Magazine - December 2013 - 25

seconds. on the other hand, fuel cells are capable of storing
et al. investigated the first rechargeable li-ion battery. High
a vast amount of energy but are limited in the peak output
capacity, energy density, and cycle life were the main
power. based on the available technologies, batteries are the
advantages of cells based on licoo2 as the positive elecbest choice to provide both power and energy densities.
trode. However, high energy release when the battery is
there are several types of batteries currently in use for
abused was a safety concern and a disadvantage of the earindustrial applications. Nickel cadmium (Nicd), lead acid,
lier batteries. lithium manganese oxide (liMn2o4) was proand li-ion are the most popular existposed to mitigate safety concerns
ing battery types. Nicd-based batterwhile representing similar voltage and
ies contain toxic metals and are
energy density, however, with faster
environmentally unfriendly. furthercapacity fading.
more, the memory effect and high
combining several lithium metal
maintenance requirements are other
oxides to take the advantage of several
drawbacks that make this type of batfeatures has created new lines of battery less favorable for industrial appliteries. the Nca type, which is a mixcations. Nickel-metal hybrids (NiMH)
ture of lithium, nickel, cobalt, and
are another type of nickel-based bataluminum oxides, and the NMc type,
tery that offers higher energy density and shorter cycle life
which is a compound of lithium, nickel, manganese, and
compared to the Nicd battery but still suffers from high
cobalt oxides, were two popular compounds based on nickmaintenance requirements due to the memory effect.
el. Having nickel in the compound increases the lifetime
lead-acid batteries are the most cost-efficient commercial batteries for power-supported applications. the
short cycle life and low energy density are the two main
Energy Density
disadvantages of these types of batteries. lead-acid batteries could be a good choice for applications in which a
Cost
Power Density
power support with low depth of discharge rate is
required. deep cycling has a serious impact on the life
cycle of the battery.
among all of the different types of energy storage currently available commercially, li-ion batteries offer the best
solution for high-power and high-energy applications.
Safety
Cycle Life
recent technologies also provide a combination of high
power and energy density with considerably high cycle and
Performance
floating lifetime (a >5,000-cycle life). li-ion batteries come in
* NMC
*
LiFePO
various types based on the chemistries for the active positive
4 * NCA
*
Lithium
Titanate
Oxide
(LTO)
and negative materials. different materials for the electrodes
*
Lead
Acid
*
LiMn
O
*
LiCoO2
2
4
lead to various battery specifications in terms of power and
energy density, voltage characteristics, life, and safety. choosFigure 4. A property comparison of several types of electrochemical
batteries.
ing the appropriate battery chemistry to meet the required
specifications of the application is
vital. similar to other battery types, liion batteries consist of two electrodes,
an anode, a cathode, a separator to
prevent shorting, and an electrolyte as
a conductor.
the cathode is a lithium metal
oxide, and common materials such as
lithium, cobalt, manganese, and iron
phosphate oxide as well as combined
chemistries including lithium nickel
cobalt aluminum oxide (Nca) or lithium manganese cobalt oxide (NMc)
are used as the cathode electrode.
lithium cobalt oxide (licoo2) has
(a)
(b)
typically been used as the positive
active material for li-ion batteries Figure 5. The schematic of the lab setup for microgrid testing: (a) 500-kVA energy storage
since 1979, when John goodenough inverter and (b) 250-kWh and 500-kW Li-ion battery.

Batteries are the
best choice to
provide both power
and energy densities.

IEEE Electrific ation Magazine / d ec em be r 2 0 1 3

Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2013