EV energy storage systems

1. Energy Storage Systems For
Electric Vehicles

3. ELECTROCHEMICAL ENERGY
STORAGE SYSTEM (EESS)
• In EV, the prime importance is given to the energy storage system that
controls and regulates the flow of energy.
• At present, the primary emphasis is on energy storage and its essential
characteristics such as storage capacity, energy storage density and
many more.
• The necessary type of energy conversion process that is used for
primary battery, secondary battery, supercapacitor, fuel cell, and
hybrid energy storage system.

4. • According to electric vehicles applications, the electrochemical, ESS
is of high priority such as batteries, supercapacitors, and fuel cells.
• An electro-chemical system deals with electrochemistry, i.e., shifting
of electrons with the help of chemical reactions at the interface of
electrode and the electrolyte (Elliott and Cook, 2018; Wu and Niu,
2017; Xia et al., 2015).
• Many other energy stored devices based on electrochemistry have
been fabricated which are named as primary and secondary batteries,
supercapacitors, fuel cells, electrolyzers and many more (Xia et al.,
2015)

5. PRIMARY BATTERY
• The first primary battery was introduced more than 100 years ago,
zinc-carbon was the only battery used in 1940 (Conway, 2013).
• After that, many advancements take place in primary cells regarding
its capacity, operating temperature, life cycle, etc., hence, there are
many primary cells designed using various anode-cathode
combinations some of them are discussed in the following
subsections (Elliott and Cook, 2018; Shen et al., 2016; Xia et al.,
2015).
• There are a variety of batteries explained below and summarized in
Table 2.

6. ZINC–CARBON AND ALKALINE
MANGANESE DIOXIDE BATTERIES
• Zinc–Carbon (Zn–C or Zn–MnO2) batteries were the most popular
battery for more than 100 years (Xia et al.,2015).
• It is also known as “dry battery”. In this, Zn is anode material while
the carbon and MnO2 are used as a cathode material (Jom et al.,
1981).
• The cathode material is based on electrolytic MnO2, which gives high
power and long life.

7. • The theoretical capacity of the primary battery, i.e., Zn–C is 225
A·h/kg, synthesized on both types of cathode material and this value is
based on simplified cells (Xia et al., 2015).
• As on a practical basis, the obtained specific capacity of the battery is
97 A·h/kg, and till now, this is the optimum specific capacity for a cell
(Xia et al., 2015).
• The operating voltage/current of the primary battery is in the range of
0.16-44 A in prismatic battery design and button cells 25-60 mA.
These batteries are having a low-temperature range, i.e., 10 ℃
(Bockris, 1981; Wendt and Kreysa, 2013)

8. ZINC-AIR BATTERY
• The zinc-air battery consists mainly of three components: a catalytic
cathode, aqueous alkaline electrolyte, and zinc powder anode (Xia et
al., 2015).
• In this, O2 is utilized from the air as an active cathode, and due to
this, the capacity of Zn-air is double than that of primary batteries.
• The gravimetric and volumetric size of a cell is very high. In the
construction of the button cell, the capacity range is 40-600 mA·h (Xia
et al., 2015).
•

9. • It has an advantage over another cell that its excellent retention even at
0 ℃ with its flats discharges curves.
• But the main problem with this battery is its life cycle as after 1-3
months the cells come into contact with the atmosphere.
• Therefore, these batteries are used in continuous-drain applications
(Xia et al., 2015)

10. SILVER-OXIDE BATTERY
• Silver-oxide battery was first synthesized in the early 1960s for
various applications such as a pocket calculator, watches, etc., as this
battery offers certain advantages over other batteries named as high
capacity, excellent storage capacity retention and a constant discharge
voltage (Xia et al., 2015).
• The theoretical energy storage capacity of Zn-Ag2O is 231 A·h/kg,
and it shows a steady discharge voltage profile between 1.5-1.6 V at
low and high discharge rates (Xia et al., 2015).
• Its main advantage is long storage life up to one year at room
temperature, and its performance deteriorates at low temperatures (-20
℃) up to 35% at standard capacity (Xia et al., 2015).

11. MAGNESIUM/MANGANESE DIOXIDE
BATTERY
• As in other batteries, now magnesium is considered as an anode material.
It has a low atomic weight and a high standard of potential.
• The main advantage of Mg battery over the other is its low operating
temperature, i.e., -20 ℃ and below (Xia et al., 2015).
• However, the low-temperature affects the performance of heat generation
during discharge and is dependent on the discharge rate, battery
configurations, battery size and many other factors (Xiaet al., 2015)

12. LITHIUM PRIMARY BATTERY
• For high energy density batteries in the 1960s, when the researchers
focused on lithium as an anode (Xia et al.,2015).
• The first lithium battery was implemented in the 1970s for military
appliances.
• The lithium battery has proved themselves to the best battery till then
because of long operational time, extreme temperature or high power
(Xia et al., 2015).
• Therefore, the primary lithium batteries can be classified into several
other categories, based on the type of anode and cathode material
discussed below (Xia et al., 2015).

13. LITHIUM-SULFUR DIOXIDE BATTERY
• The first lithium commercialized cell was introduced in the 1970s, i.e.,
lithium-sulfur dioxide (Li-SO2) cells
• (Broussely and Pistoia, 2007). In this cell, carbon is placed as a
cathode and lithium used as an anode. Teflon bonded acetylene black
supported on Al screen also serves as a cathode due to which cell
provides high values
• of surface area, conductivity, and porosity (Xia et al., 2015). This has
high conductivity even at -50 ℃ (2.2 × 10-2 Ω-1·cm-1), and working
voltage are 2.7-2.9 V (Zhang, 2012).

14. • As the tubular construction also provides a good energy density of
≈260 W·h/kg and its storing capacity is 34 A·h (Xia et al., 2015).
• However, the primary concern of this battery is its passivating film,
which starts reducing its capacity when the concentration of SO2 is
• below 5% (Xia et al., 2015)

15. LITHIUM-THIONYL CHLORIDE
BATTERY
• These batteries were used because of their efficient energy density of
440- 610 W·h/kg and the long-life span of 14-21 years (Xia et al.,
2015).
• Moreover, certain batteries can be operated at an extensive
temperature range-80 ℃ to 150 ℃ (Xia et al., 2015).
• As similar to a Li-SO2 battery, Li-SOCl2 also has porous carbon as a
cathode, the solvent for the electrolyte salt and SOCl2 acts as an
anode.
• In this, the main component to form the passivating film on the anode
is LiCl. Hence, to increase the capacity of cell AlCl3 is adding in
excess to the electrolyte (Xia et al., 2015)

16. LITHIUM-MANGANESE DIOXIDE
BATTERY
• Li-MnO2 was introduced in 1975 and also known as solid-cathode
primary batteries (Broussely and Pistoia,2007).
• These are widely used due to certain advantages followed as relatively
high energy density, high working voltage, nominal operating
temperature range (350 ℃–400 ℃), long lifespan, and low cost (Xia
et al., 2015).
• The most widely used electrolyte is LiClO4-PC-DME. Li-MnO2 can
be constructed in various forms according to its applications such as
cylindrical, cover coin and prismatic structures (Xia et al., 2015).

17. Lithium-carbon monofluoride battery
• Another solid-cathode primary battery is made with Li-C
monofluoride (Li-CFx) battery, in which polycarbonate fluoride is
used as a cathode (Xia et al., 2015).
• In this, Carbon enhances the electronic conductivity of the cathode
material.
• Hence, the CFx system has advanced features and shows the flat
operating voltage profile (2.8 V), energy density (200 to 600 W·h/kg),
high capacity and full temperature range (-40 ℃ to 85 ℃ and reached
up to 125 ℃ depends upon design) (Xia et al., 2015).

18. • Also, Li-CFx also shows the self-discharge rate among all lithium
batteries. Although there are many more lithium primary batteries,
which are designed for various types of applications such as cell
phones, notebooks, etc