Technology to increase energy density of electric car batteries
V. I. ZUBTSOV
Department of Construction Industry
Polotsk State University
Novopolotsk, BELARUS
Abstract: The article deals with a small-sized unit developed using ferro-piezoelectric ceramics for electric
power generation. The use of an electrochemical generator in the unit makes it possible to increase the
efficiency of electricity generation by controlling the polarization of ferro-piezoelectric ceramics. At the
consumption of 1 joule of electricity, using mechanical energy, 3, 5...5 joules of output electrical energy are
generated. The increase in the energy density of the batteries occurs in two stages: the first stage is to increase
the degree of polarization of the segmentelectric, the second stage is to increase the electrical power to the
load.
The power plant efficiency is about 55...60 percent and depends on the ceramic modification and the electric
circuit.
Keywords: Energy, power, voltage, polarization, technology, vehicle batteries
Received: September 8, 2021. Revised: June 21, 2022. Accepted: July 11, 2022. Published: September 2, 2022.
1. Introduction
Most countries are focused on achieving carbon
neutrality. That is why electric cars are now being
rapidly adopted. The mass transition to electric
cars will require a large amount of additional
electricity and the creation of networks of chargers
and charging stations.
The range of an electric car on a single charge
is much less than consumer demand. Its energy
source (batteries) weighs a lot and costs a lot .
The reason is that the energy density of modern
batteries is too low. Although the energy density
of batteries has recently almost doubled, they still
have a large weight, size and cost. Known simple
ways to increase the energy density of batteries are
almost exhausted. In order for batteries to replace
traditionally used internal combustion engines,
their energy density should be increased
approximately 10-15 times. The use of solar and
wind energy is still inefficient. In addition, the
national interests of hydrocarbon-producing
countries are a deterrent to the development of
electric vehicles. Thus, the problem of battery
energy requires a solution.
Toyota's solid-state batteries, which promise to
greatly increase energy density, are still under
development. And it could be a decade or more
before these batteries become mass-produced.
2. Brief description of the design and
operation of the power plant.
Mathematical justification of
polarization and electrical voltage
increase of an electrochemical
generator
In connection with the above, a small-sized power
unit (EU) of an alternative innovative technology
using an electrochemical generator (ECG) based
on ferro-piezoelectric ceramics was developed.
Such an EU simultaneously increases the specific
power and specific energy (energy density) of the
batteries. Currently, there are opportunities to
obtain significant electric currents (bias currents)
in dielectrics by improving the electrical
characteristics of ferro-piezoelectric ceramics and
physical-technical solutions (technologies) [1]. In
experimental dependences of output electric
voltage on mechanical load of ferro-piezoceramic
elements of various modifications and connection
circuits are given [2].
Efficient use of ferroelectrics requires the
development of a system that allows, compared to
the electric drive devices currently used, to spend
less energy from batteries and to increase the
efficiency of converting mechanical energy into
electrical energy due to the electrical
characteristics of ferro-piezoelectric ceramics and
physical-technical solutions (technologies). An
increase in the energy density of batteries by
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2022.4.6
V. I. Zubtsov
E-ISSN: 2769-2507
40
Volume 4, 2022
3.5...5 times is achieved by modifying ferro-
piezoelectric ceramics, electric circuit, mechanical
loading conditions, second-order ferroelectric
transition, and interlayer and dipole polarization
[2]. EU (interacting electromechanical transducer,
device for mechanical energy generation and
ECG), figure 1, increases the energy density of the
battery in two stages: in the first stage there is an
increase in the degree of polarization of ECG, in
the second - an increase in the electrical power Рн
at the output of EU, that is at the load.
In brief, the principle of operation of ECG,
which is the main unit of the plant for increasing
the energy density of batteries, is to release
"frozen" energy of chemical reaction of oxidant
and a ferro-piezoelectric ceramic element, which
is a multi-component system of solid solution.
Structurally ECG is ferro-piezoelectric ceramic
element of a certain size and shape with metal
contacts and attached leads for its connection to
an electric circuit. Taking into account the use of
mechanical energy, the power plant efficiency is
50 ... 55%. Consumption of 1 J of battery energy
using mechanical energy makes it possible to
obtain the output of 3.5...5 J of electrical energy
at the output of the power plant. Used
mechanical energy is generated by a device of
simple construction [1, 3].
Figure 1. Functional diagram EU.
An increase in the degree of polarization of
ferro-piezoelectric ceramic elements is achieved
by controlling their compressibility and energy
elasticity [2, 4].
The constructions of the electromechanical
transducer and ECG, in addition to ferro-piezo
electric elements, which can be represented as a
resonant circuit, have other secondary elements.
Therefore, in dynamics, these spring-mass
structures have a complex spectrum of their own
frequencies and in an electric circuit represent a
series-parallel circuit [2, 5], which has two
frequency constants: two resonances – a series
one with frequency fr and a parallel one (the so-
called antiresonance) with frequency fa.
We present the unknown expressions for fr
and fа.
(1)
Thus, it is possible to determine
approximately the resonance and antiresonance
frequencies, which is important for calculating
the technical specifications for the EU.The
increase in the degree of ECG polarization is
explained as follows. Tthe equations of
transformation for the plant of this construction
and ferro-piezoelectric ceramics under active
mechanical stress and closed output electrodes
and Е=0 is following:
SE = sET
DE = PE = dT (2)
SE goes for deformation under field strength of,
E=0; sE is compliance under E=0;
D goes for displacement when E=0; P means
polarization when E=0.
The field with mechanical stress equal to E is
used in case of open electrodes and the lack of
strain (mechanical stresses T=0), when the
element can be easily deformed. The equation is
following:
ST = dE
DT =
E (3)
ST means deformation under T=0, different from
SE, DT also differs from DE.
If then decided that the electrodes are open and
the field strain E and mechanical stress T influence
simultaneously, and displacement D=0, then an
interdependence between E and T can be found:
T = -
E, or
SD =
T = sDT
Where D is less than SE. It is clear that electric
field E can be applied for changing elastic
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2022.4.6
V. I. Zubtsov
E-ISSN: 2769-2507
41
Volume 4, 2022
compliance s of ferroelectrics, i.e. for control of its
rigidity (compressibility). An increase in
compressibility is associated with an increase in
deformation, and this is equivalent to the result of
an increase in mechanical stress Т, (2)
If Е and Т influences imultaneously, and
deformation S=0, i.e. the element is pressed and
does not deform, then an interdependence between
mechanical stress T and electric field strain E is
observed:
T = -
E
displacement D is found by the expression [4]:
DT =
E =
(4)
Absolute dielectric constants of the pressed
element
is obviously less than
(3) and they
are described in equation (5), К is an
electromechanical coupling factor (a kind of
efficiency of the material in the conversion of
mechanical energy into electrical energy and vice
versa):
=
(5)
s E goes for electric field strain compliance Е=0
is an absolute dielectric constant under
mechanical stress T=0. Controlling the
compressibility and electroelasticity of ferro-
piezoceramic elements in the installation makes it
possible to increase the sensitivity of the output
electrical voltage of these elements to the acting
mechanical loads.
Thus, the control of compressibility and
electrical elasticity of ferropoiezoelectric ceramic
elements in the installation makes it possible to
increase the electromechanical coupling
coefficient K, i.e., their polarization [1, 4].
As already mentioned, the increase in battery
energy density occurs in two stages. And the
second stage is explained as follows. The degree
of polarization depends on the magnitude of the
charge on the surface of the ferroelectric. In a
certain frequency range between resonance and
antiresonance (1), where the strain will increase
dramatically to a greater extent than it does due to
mechanical loading, there is a sudden absorption
of mechanical energy. This leads to a dramatic
increase in the degree of polarization. A decrease
in the electrical capacitance of the ECG
segmentelectric leads to an increase in the
electrical voltage U, and hence an increase in the
electrical power Рн in the load.
At frequencies well below resonance, the
equivalent circuit of the ECG [5, 6] is capacitive in
nature and can be simplified as shown in Fig. 2.
The electric charge is the natural output of the
ECG. If it fluctuates according to the sinusoidal
law, Fig. 2, we have [2]
q = Q0 sin(t) =CU + idt, (6)
where Q is the amplitude value of the ECG charge,
but
RIU
, then
tcos
R
Q
I
R
1
dt
Id
C
0
C
(7)
The final solution of this equation will be of the
form:
c
R
t
e
2
C
1U
R
1
arctgtsinUU ω
ω
, (8)
where
2
0
1
RC
1
1
C
Q
U
(9)
U
R
C
i
Fig. 2. Simplified equivalent diagram of
the ECG, reflecting
its capacitive nature of electrical
resistance.
g
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2022.4.6
V. I. Zubtsov
E-ISSN: 2769-2507
42
Volume 4, 2022
g - electric charge generated by the piezo
effect;
C - capacitance of the ECG;
R - internal resistance of the battery, power
plant load;
U - output electric resistance of the ECG.
RC
RC
1C
Q
U0
2ω
ω
(10)
Expression
0
0U
C
Q
- this is the amplitude
value of the voltage that appeared on the
capacitance С at
R
. It follows from
expression (8) that the output voltage U depends on
the frequency , where the first term of equation (9)
is proportional to the measured physical quantity,
i.e. mechanical stress: an increase in mechanical
load, as is known, is accompanied by an increase in
the charge on the piezoelectric element, and an
increase in the charge
0
Q
, as follows from
equation (9), leads to an increase in voltage
1
U
;
the second term characterizes the ECG in the
transient mode, it disappears at large values RC, see
equation (10). We transform expression (9) to such
a form that it is possible to establish the dependence
1
U
, from :
2
0
1
RC1
RC
U
U
. (11)
Using (11), we construct the dependence
0
U
1
U
from RC, fig. 3.
Curve in Fig. 3 is part of the experimental
amplitude-frequency response of an
electromechanical piezotransducer, see in [2] in fig.
4. 1 (curve 2), in the frequency range between anti-
resonance and resonance. Piezoconverter is made of
the segnelectric PZT-19, with a diameter of 10x1 mm
with a mechanical load of 2.5 MPa.
From Fig. 3 it is obvious that increasing leads
to increasing
1
U
, and hence the output voltage U,
see equation (8).
Thus, in a certain frequency range between
resonance and antiresonance there is a sharp
increase in the degree of polarization of the
segmentelectric, which leads to an increase in the
electrical voltage at the ECG output (increase of the
charge g on its surface) and, consequently, the
electrical powerMoreover, today there are
multicomponent ferro-piezoelectric ceramics of a
considerably higher electromechanical coupling
factor K than a PZT system.
Tests proved that 2 times increase (decrease) of
a load electric power (Рн) causes 2√2 times, 3
times - 3√3 etc., increase (decrease) of ECG mass .
All the changes follow the principles of geometric
progression. More details about this are given in
[1, 5, 7, 8].
The technology has no analogues. The main
components of the EU are protected by copyright
certificates and patents [2, 3], and the performance
has been tested in experimental studies.
0.01 0.02 0.05 0.1 0.5 1 2510 20
1.00
0.75
0.5
0.25
0
U1/U0
RC
Fig. 3. Frequency response of ECG.
3. Conclusion
The proposed alternative innovative technology to
increase the energy density of batteries compared
to solar and wind energy has advantages: it does
not depend on climatic conditions and time of day
and has high efficiency. Segnetoelectrics are
relatively cheap to produce [9, 10], while lithium
ion batteries are very expensive to produce and
only the more efficient batteries currently being
designed will be even more expensive. The weight
and cost of the electric car will increase slightly
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2022.4.6
V. I. Zubtsov
E-ISSN: 2769-2507
43
Volume 4, 2022
due to the presence of the EU. If you use an EU
with the same range on a single charge, the weight
and cost of the electric car will decrease, as the
battery pack will be reduced by 3.5 times.
Controlling the degree of polarization of
ferroelectrics and increasing the energy density of
batteries is mainly determined by the following:
- The modification of ferroelectrics and the
electrical connection scheme;
- Mechanical loading (design features of the
EU);
- interlayer or dipole polarization of ferroelectrics
in the frequency range of the order of 1...1.5 (103 -
105) Hz.
References:
[1] Zubtsov V I , Zubtsova E V and V V Derugin
The technology of increasing the energy density of
batteries by controlling the degree of polarization of
ferroelectrics. Jornal of Physics: Conf. Series 1400,
066061, 2019.
[2] Zubtsov V.I. Control of the physical properties
of materials using piezoelectrics. Riga:
LAP LAMBERT Academic Publishing, 2020. - 262
p.
[3] Zubtsov V.I., Zubtsova Е.V. Segnetoelek ics in
improving the efficiency of electric vehicles/
(Europe an Union: LAP LAMBERT Academic
Publishing), 2021 - 54 p.
[4] Okazaki K. Manual on Electrical Materials
(Moscow: Mechanical Engineering), 1979, - p. 432.
[5] Zubtsov V I , Zubtsova E V, Senterova V. V.
Control of ferroelectrics polarization for increasing
of alternative energy device’s efficiency coefficient.
IOP Conf. Series: Journal of Physics: Conf. Series
1038, 012113, 2018.
[6] Zubtsov V.I., Zubtsova Е.V. Ferroelectric
polarization control in technology for reducing
power consumption when charging batteries
// International Journal of Power Systems. – 2022. –
No. 7. - pp. 10-14.
[7] V. I. Zubtsov, A.V. Zubtsova. Ecologically clean
power plant to increase energy consumption by
transport batteries // Ecological systems and
devices. - 2019 - No. 5. - P.38-43.
[8] Zubtsov V.I. Efficiency of ferroelectrics
application in technologies of simultaneous increase
of specific capacity and electric drive power of light
electric vehicles and alternative energy devices.
Jornal of International science project. - 2017 -
No7. - pp 15-20.
[9] Zubtsov V.I. Application of ferroelectrics in
technologies for simultaneous increase in specific
power and specific energy of light transport electric
drive//Mat. intl. conf. on physics and astronomy
/FTI im. A.F. Ioffe. - St. Petersburg, 2018 - pp. 243-
244.
[10] Zubtsov V.I. Application of Segantoelectrics
to Increase Drive Efficiency of Electric Vehicles
//Mat. intl. conf. on physics and astronomy /FTI im.
A.F. Ioffe. - St. Petersburg, 2021 - pp. 273-274.
International Journal of Electrical Engineering and Computer Science
DOI: 10.37394/232027.2022.4.6
V. I. Zubtsov
E-ISSN: 2769-2507
44
Volume 4, 2022
Creative Commons Attribution License 4.0
(Attribution 4.0 International, CC BY 4.0)
This article is published under the terms of the Creative
Commons Attribution License 4.0
https://creativecommons.org/licenses/by/4.0/deed.en_US
