scispace - formally typeset

Journal ArticleDOI

A self-discharge model of Lithium-Sulfur batteries based on direct shuttle current measurement

30 Dec 2016-Journal of Power Sources (Elsevier)-Vol. 336, pp 325-331

Abstract: In the group of post Lithium-ion batteries, Lithium-Sulfur (Li-S) batteries attract a high interest due to their high theoretical limits of the specific capacity of 1672 Ah kg−1 and specific energy of around 2600 Wh kg−1 However, they suffer from polysulfide shuttle, a specific phenomenon of this chemistry, which causes fast capacity fade, low coulombic efficiency, and high self-discharge The high self-discharge of Li-S batteries is observed in the range of minutes to hours, especially at a high state of charge levels, and makes their use in practical applications and testing a challenging process A simple but comprehensive mathematical model of the Li-S battery cell self-discharge based on the shuttle current was developed and is presented The shuttle current values for the model parameterization were obtained from the direct shuttle current measurements Furthermore, the battery cell depth-of-discharge values were recomputed in order to account for the influence of the self-discharge and provide a higher accuracy of the model Finally, the derived model was successfully validated against laboratory experiments at various conditions
Topics: Self-discharge (60%), State of charge (53%)

Content maybe subject to copyright    Report

A Self-discharge Model of Lithium-Sulfur Batteries Based on Direct Shuttle
Current Measurement
Author Names: Vaclav Knap
a,*
, Daniel-Ioan Stroe
a
, Maciej Swierczynski
a
, Rajlakshmi
Purkayastha
b
, Karsten Propp
c
, Remus Teodorescu
a
and Erik Schaltz
a
Affiliation(s):
a
Department of Energy Technology, Aalborg University, Aalborg, 9000,
Denmark
b
Oxis Energy Ltd, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB, United
Kingdom
c
Centre for Automotive Engineering and Technology, Cranfield University, Bedfordshire
MK43 0AL, United Kingdom
*
Corresponding Author. Tel: +45 20294922, Fax: +45 9815 1411 E-mail Address:
vkn@et.aau.dk
In the group of post Lithium-ion batteries, Lithium-Sulfur (Li-S) batteries attract a high
interest due to their high theoretical limits of the specific capacity of 1672 Ah kg-1 and
specific energy of around 2600 Wh kg-1. However, they suffer from polysulfide shuttle, a
specific phenomenon of this chemistry, which causes fast capacity fade, low coulombic
efficiency, and high self-discharge. The high self-discharge of Li-S batteries is observed
in the range of minutes to hours, especially at a high state of charge levels, and makes
their use in practical applications and testing a challenging process. A simple but
comprehensive mathematical model of the Li-S battery cell self-discharge based on the
shuttle current was developed and is presented. The shuttle current values for the model
parameterization were obtained from the direct shuttle current measurements.
Furthermore, the battery cell depth-of-discharge values were recomputed in order to
account for the influence of the self-discharge and provide a higher accuracy of the
model. Finally, the derived model was successfully validated against laboratory
experiments at various conditions.
Keywords: Lithium-Sulfur battery, self-discharge, polysulfide shuttle, modelling,
validation.
1. Introduction
Lithium-Sulfur (Li-S) batteries represent a promising alternative to the Lithium-ion
battery chemistry, due to their high theoretical limits in terms of specific capacity (i.e.
1672 Ah kg-1) and specific energy (i.e. 2600 Wh kg-1). Furthermore, they are expected
to become a cheaper and more environmentally friendly solution, mainly due to the use
of sulfur, which is an abundant and benign element. However, besides other chemistry
related phenomena, Li-S batteries suffer from polysulfide shuttle, which results in several
commonly known drawbacks: fast capacity fade, low coulombic efficiency, and high
self-discharge [1], [2]
.
For the practical use of the Li-S batteries, there is a need not only to characterize the
self-discharge behavior as it was done in [3], but also to provide a proper simulation tool
(a model), relevant for industrial applications and laboratory experiments as well;
otherwise, biased results can be acquired (e.g. not corresponding depth-of-discharge
(DOD) levels assigned). The main cause of self-discharge for Li-S cells was identified to
be the polysulfide shuttle and afterwards the corrosion of the current collectors [4], [5],
Journal of Power Sources, Volume 336, 30 December 2016, Pages 325331
DOI: 10.1016/j.jpowsour.2016.10.087
Published by Elsevier. This is the Author Accepted Manuscript issued with: Creative Commons Attribution Non-Commercial No Derivatives License (CC:BY:NC:ND 4.0).
The final published version (version of record) is available online at http://dx.doi.org/10.1016/j.jpowsour.2016.10.087. Please refer to any applicable publisher terms of use.

[6], [7]. Because the polysulfide shuttle is present not only during the cell idling, but also
during charging and discharging, the self-discharge appears as well during these
conditions. A mechanistic model of the polysulfide shuttle causing the self-discharge of
the Li-S battery cells was presented in [8]. However, the purpose of the model was to
provide insights into the key battery mechanisms, rather than to be used from an end-
application perspective. The mathematical model presented in [9] and a zero dimensional
model for the Li-S batteries introduced in [10] are using the relations for the polysulfide
shuttle derived from [4]. However, these relations are based on determining
experimentally a shuttle constant k
S
, which is a time-consuming procedure; moreover, it
might not always provide sufficiently accurate results for the self-discharge estimation, as
it was indicated in [3]. Another simple approach was used in [11], where the self-
discharge current was related to the charge lost during idling at 100 % state-of-charge
(SOC). The self-discharge current was identified to be proportional to the square root of
the idling time. However, the model characterization tests for the 100 % SOC condition
took more than nine days and it was assumed that self-discharge current is dependent on
the used power profile. Furthermore, a methodology for direct shuttle current
measurement was proposed in [12], where its results were analyzed and validated using
the one-dimensional phenomenological model, which is based on Nernst and species
concentrations equations. This methodology allows for a simple and time-effective
measurement of the shuttle current at different SOC levels; it is based on the premise that
the shuttle current can be observed as the steady-state current flows through the cell,
while its voltage is kept constant during constant voltage operation to prevent the voltage
decay.
In this paper, the direct shuttle current measurement method is used to identify the
shuttle current of a 3.4 Ah Li-S pouch cell at different depth-of-discharge levels and
temperatures. Furthermore, the obtained results are used to derive a simple and easy-to-
use mathematical model of the self-discharge in the Li-S battery cell that is related to the
polysulfide shuttle phenomenon. This model is validated against several self-discharge
experiments at various conditions and it is suitable to predict the self-discharge during
idling and operation of the battery.
2. Methodology
The work flow followed in this paper is summarized and presented in Fig. 1. At first,
the measurements were performed and they are described in Section 2.1 for direct shuttle
current measurements and in Section 2.2 for the self-discharge model validation
measurements. The current shuttle measurement results are presented in Section 3 and
later on in Section 3.1 it is also shown how the mathematical expression for the self-
discharge model dependent on DOD and temperature is derived. Later on, there were
considered three fitting cases. Fitting Case 1 (Section 3.1.1) uses the pre-determined
DOD points to develop the model, Fitting Case 2 (Section 3.1.2) recomputes and
‘corrects‘ the DOD points according consideration of the self-discharge ongoing during
the measurements and Fitting Case 3 (Section 3.1.3) adds up simulation of the
measurement to update the DOD points. Each of these fitting cases parameterize the self-
discharge model and its accuracy is later validated in Section 3.2 by an use of the
validation measurements (Section 2.2) and the SOC estimation model for the validation
(Section 2.3) with the consideration of the total capacity concept (Section 2.4). The
discussion about SOC reference frame and cell history effect, which are related to the
self-discharge model integration and use, is hold in Section 4.1. Furthermore, the

alternative version of the self-discharge model considering dependence on the open-
circuit voltage rather than DOD is discussed in Section 4.2.
Figure 1. Work flow scheme used for the self-discharge model derivation and validation.
All the measurements were performed on a single 3.4 Ah long life chemistry Li-S
pouch cell manufactured by OXIS Energy. A Digatron BTS 600 battery test station was
used for the direct shuttle current measurement procedure. To avoid battery cell
overcharging and in order to reduce the degradation of the cell at a high current shuttle
region, for all the charging conditions, charging time limitations were applied as well (8.5
hours for 15 °C, 9 hours at 25 °C and 10.5 hours for 35 °C). The values of 0.1 and 0.2 C-
rate correspond to 0.34 and 0.68 A currents, respectively.
2.1 Direct Shuttle Current Measurement
The applied test procedure for the direct shuttle current measurement is based on the
methodology presented in [12] and illustrated in Fig. 2. The procedure started with two
nominal cycles: 0.1 C-rate constant current charging until 2.45 V and 0.2 C-rate
discharging to 1.5 V. The first cycle served as a pre-condition cycle, which is needed in
order to ‘reset’ the cell’s history (as the Li-S is a soluble chemistry) and to bring the cell
to the similar initial condition at the selected temperature. The second cycle was used for

the cell’s capacity check and its calculation for the further procedure steps. Afterwards,
the cell was charged fully (by 0.1 C-rate to 2.45 V) and discharged (by 0.2 C-rate) to a set
DOD point (i.e. 2 %). Then, the cell was rested in open circuit condition in order to reach
an open-circuit voltage (OCV) value. The OCV is considered as an equilibrium voltage
point, which is the peak value between voltage rise during the recovery period and
voltage fall during the predominant self-discharge. However, in practice, due to the noise
in the voltage signal, the reliable value of the OCV was determined when the battery
voltage dropped from the maximum point by 0.6 mV (three times the value of the battery
test station accuracy which was equal to 0.2 mV) as it is presented in Fig. 3. In the next
step, these detected OCV value was used later in two hours constant voltage charging, in
order to determine the steady-state current as it is presented in Fig. 3. This steady-state
current is considered as the shuttle current. All these above mentioned steps are repeated
for other DOD values (2 % step resolution until 30 % DOD or until there is no detection
of the voltage peak in a 12 hours relaxation period). The voltage and current signals
during the direct shuttle current measurement procedure are shown in Fig. 3 for DOD
equal to 10 % at 35 °C. Next, the direct shuttle current measurement procedure was
repeated for other temperatures (15, 25 and 35 °C). The whole measurement procedure,
(including the two full cycles performed in the beginning), lasted between 4 and 4.5 days
for each of the considered temperatures.
Figure 2. Overall test procedure for the direct shuttle current measurement.
Figure 3. Illustration of current and voltage signals during the direct shuttle current
measurement.
2.2 The Measurements for Validation of the Self-Discharge Model

The self-discharge measurement procedure is based on the methodology presented in
[3] and it is illustrated in Fig. 4. At first, a pre-condition cycle and capacity check cycle
were performed, the same as in the case of the direct shuttle current measurement. This
step was followed by charging the cell (by 0.1 C-rate to 2.45 V) and discharging (by 0.2
C-rate) to a pre-determined DOD value (this discharging step was skipped for 0 % DOD).
Then, the cell was kept at open circuit condition (“relaxation stage”) for a specific time
and afterwards fully discharged (by 0.2 C-rate to 1.5 V).
Figure 4. Test procedure for the self-discharge model validation.
2.3 Matlab/Simulink Model for Validation
The self-discharge Li-S model is going to be integrated into a Matlab/Simulink model,
which allows for SOC estimation based on the coulomb counting method. The used SOC
definition in this work follows the definition described in [13]. So the SOC represents the
relation between the actual useable battery capacity (C
a
) and the total capacity (C
t
)
available to be discharged after the battery being fully charged. This expressed in
percentage is written as SOC=C
a
/C
t
*100. Using only coulomb counting method, without
accounting for the fast self-discharge of the Li-S batteries will lead inevitably to a
growing error due to not capturing the self-discharge current. The SOC estimation model
is driven by following equations:
SOC = SOC
ini
+ (-(I+I
sh
)*100/(C
t
*3600)*dt) (1)
DOD = 100 – SOC (2)
Where SOC is the actual state-of-charge, SOC
ini
is the initial state-of-charge, I is the
applied current (discharging current has positive sign orientation), I
sh
is the shuttle current,
C
t
is the total capacity of the cell at the specific temperature, and DOD is the depth-of-
discharge.
2.4 Concept of the total capacity of the Li-S batteries
The standard practice to determine the capacity of Li-S battery cells is to
continuously discharge before-hand fully charged battery by a specific current at a
specific temperature. The obtained discharged capacity is considered as the capacity of
the cell at those conditions. However, as the polysulfide shuttle is present during the Li-S
cell discharging, it causes self-discharge, which consequently reduces the measured
capacity. Therefore, the term of total capacity C
t
of the cell is introduced as follows:

Citations
More filters

Journal ArticleDOI
X. Zhang, Haiming Xie1, Chisu Kim2, Karim Zaghib2  +2 moreInstitutions (3)
Abstract: This review is focused on the state-of-the-art of lithium-sulfur batteries. The great advantage of these energy storage devices in view of their theoretical specific capacity (2500 Wh kg −1 , 2800 Wh L −1 , assuming complete reaction to Li 2 S) has been the motivation for a huge amount of works. However, these batteries suffer of disadvantages that have restricted their applications such as high electrical resistance, capacity fading, self-discharge, mainly due to the so-called shuttle effect. Strategies have been developed with the recent modifications that have been proposed as a remedy to the shuttle effect, and the insulating nature of the polysulfides. All the elements of the battery are concerned and the solution, as we present herewith, is a combination of modification of the cathode, of the separator, of the electrolyte, including the choice of binder, even though few binder-free architectures have now been proposed.

78 citations


Journal ArticleDOI
Gabriela Benveniste1, H. Rallo2, L. Canals Casals1, A. Merino3  +1 moreInstitutions (3)
TL;DR: This paper presents a review of the state of art of Li-Sulphur battery on EVs compared to Li-ion ones, considering technical, modelling, environmental and economic aspects with the aim of depicting the challenges this technology has to overcome to substituteLi-ion in the near future.
Abstract: The market share in electric vehicles (EV) is increasing. This trend is likely to continue due to the increased interest in reducing CO2 emissions. The electric vehicle market evolution depends principally on the evolution of batteries capacity. As a consequence, automobile manufacturers focus their efforts on launching in the market EVs capable to compete with internal combustion engine vehicles (ICEV) in both performance and economic aspects. Although EVs are suitable for the day-to-day needs of the typical urban driver, their range is still lower than ICEV, because batteries are not able to store and supply enough energy to the vehicle and provide the same autonomy as ICEV. EV use mostly Lithium-ion (Li-ion) batteries but this technology is reaching its theoretical limit (200–250 Wh/kg). Although the research to improve Li-ion batteries is very active, other researches began to investigate alternative electrochemical energy storage systems with higher energy density. At present, the most promising technology is the Lithium-Sulphur (Li-S) battery. This paper presents a review of the state of art of Li-Sulphur battery on EVs compared to Li-ion ones, considering technical, modelling, environmental and economic aspects with the aim of depicting the challenges this technology has to overcome to substitute Li-ion in the near future. This study shows how the main drawbacks for Li-S concern are durability, self-discharge and battery modelling. However, from an environmental and economic point of view, Li-S technology presents many advantages over Li-ion.

31 citations


Cites methods from "A self-discharge model of Lithium-S..."

  • ...…and Chen, 2014c) Martin Rolf Busche 2014 Cell Shuttle-effect at different temperatures and different rates (Busche et al., 2014) Vaclav Knap 2016 Battery A self-discharge model based on direct shuttle current measurement (Vaclav Knap et al., 2016) Peng Tan 2017 Battery Mass…...

    [...]

  • ...Even though, as explained above, the shuttle effect has several undesired consequences on LiS batteries, Vaclav Knap et al. make use of this effect to introduce a new type of passive dissipative balancing method, based on electrochemistry, which allows to take better advantage of the total capacity....

    [...]

  • ...Abdollahi et al., 2017) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Abbas Fotouhi 2017 Cell Equivalent Circuit Network Model Parameterization and Sensitivity Analysis (Fotouhi et al., 2017b) Vaclav Knap 2017 Battery Model to study the selfbalancing feature (Knap et al., 2017) Daniel-Ioan Stroe 2017 Battery Modelling the discharge phase (Stroe et al., 2017) Abbas Fotouhi 2017 Battery SOC observability Analysis and Estimation (Fotouhi et al., 2017c) S. E. A. Yousif 2018 Battery Self-Discharge Effects in Lithium- Sulphur Equivalent Circuit Networks (Yousif et al., 2018) Table 2: Li-S models classifieds by the type of model Due to the computational limitations of the microprocessors on board EVs and that they execute many tasks besides those related to the battery; battery models implemented on EV should demand low computational resources....

    [...]

  • ...Karthikeyan Kumaresan 2008 Cell Physical reasons for the two- stage discharge profile (Kumares an et al., 2008) Mahmoudrez a Ghaznavi, P. Chen 2013 Cell Applied discharge current and cathode conductivity (Ghaznavi and Chen, 2014a) Mahmoudrez a Ghaznavi, P. Chen 2013 Cell Precipitation reaction kinetics and Sulphur content (Ghaznavi and Chen, 2014b) Mahmoudrez a Ghaznavi, P. Chen 2014 Cell Variation of the exchange current densities, diffusion coefficients, and cathode thickness over a wide range (Ghaznavi and Chen, 2014c) Martin Rolf Busche 2014 Cell Shuttle-effect at different temperatures and different rates (Busche et al., 2014) Vaclav Knap 2016 Battery A self-discharge model based on direct shuttle current measurement (Vaclav Knap et al., 2016) Peng Tan 2017 Battery Mass transport and electrochemical reaction processes is first developed (Tan et al., 2017) Zhaofeng Deng 2013 Battery Modelling and Analysis of Capacity Fading (Deng et al., 2013) Andreas F. Hofmann 2014 Battery Shuttle and capacity loss (Hofmann et al., 2014) Teng Zhang 2015 Cell Modelling the voltage loss mechanisms (Zhang et al., 2015) Y.X. Ren 2016 Battery Discharge behaviour incorporating the effect of Li2S precipitation (Ren et al., 2016) Monica Marinescu 2016 Battery Dimensional model during charge and discharge (Marinesc u et al., 2015) Mahsa Ebadi 2017 Battery Modelling the Interfacial Chemistry of the LiNO3 Additive (Ebadi et al., 2017) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 Nisa Erisen 2018 Battery Predict the effect of critical cathode design parameters (Erisen et al., 2018) Vaclav Knap 2018 Battery Test Methodology for Degradation Assessment (Knap et al., 2018) Monica Marinescu 2018 Battery Irreversible vs Reversible Capacity Fade during Cycling: The Effects of Precipitation and Shuttle (Marinesc u et al., 2018) Saul Perez Beltran 2018 Battery New understanding of graphene effects on S reduction behaviour (PerezBel tran and Balbuena, 2018) Chen 2006 Battery prediction of the remaining battery capacity of Lithium-ion batteries (Chen et al., 2006) O. Erdinc 2009 Battery Effects of temperature and capacity fading (Erdinc et al., 2009) Natalia A. Cañas 2012 Battery Equivalent circuit model using electrochemical impedance spectroscopy (Cañas et al. 2013) Suguna Thanagasund ram 2012 Cell Cell model for battery simulation (Thanaga sundram et al., 2012) Vaclav Knap 2015 Battery Parametrization Techniques for an Electrical Circuit Model (Knap et al., 2015b) Vaclav Knap 2015 Battery Performance Modelling (Knap et al., 2015a) Abbas Fotouhi 2015 Battery Electric Vehicle Battery Model Identification and State of Charge Estimation in Real World Driving Cycles (Fotouhi et al., 2015) Abbas Fotouhi 2016 Battery Prediction-Error Minimization (PEM) algorithm applied to experimental data (Fotouhi et al., 2016c) Abbas Fotouhi 2016 Cell Graphical User Interface for Battery Design and Simulation; From Cell Test Data to RealWorld Automotive Simulation (Fotouhi et al., 2016d) Abbas Fotouhi 2016 Battery Model in real-time applications where accuracy is important (Fotouhi et al., 2016a) Karsten Propp 2016 Battery Non-linear state-of-charge dependent ECN model (Propp et al., 2016) Ali Abdollahi 2017 Battery Optimal charging for general equivalent electrical battery model, and battery life management....

    [...]

  • ...Moreover, Li-S batteries have 8-15% self-discharge rate per month (Kolosnitsyn and Karaseva, 2008)(V. Knap et al., 2016) due to polysulfide shuttle (Mikhaylik and Akridge, 2004) and collector corrosion (Song et al., 2013), (Vaclav Knap et al., 2016), (Marinescu et al., 2015), which is between 10 and 15 times higher than the selfdischarge of Li-ion batteries (Table 1)....

    [...]


Journal ArticleDOI
Abstract: Experimental data elucidating the time-dependent composition of the electrolyte within a standard lithium-sulfur battery cell are presented. The electrolyte employed consisted of a solution of LiTFSI in a 1:1 mixture of dimethoxyethane and dioxolane, including nitrate salts. In order to track the decomposition reactions of the electrolyte components, the cells were run for a fixed number of cycles, after which they were opened and the remaining electrolyte was extracted with an excess amount of 1,4-dioxane. The amount of each of the components (namely LiTFSI, dimethoxyethane and dioxolane) within these mixtures was determined by means of gas chromatography and 19 F-NMR. It was found that the amount of electrolyte accessible to extraction remains relatively constant during the first 25 cycles, but then continuously decreases within the subsequent 40 investigated cycles. The ratio of the organic constituents of the electrolyte does not change considerably, which means there is no preferred decomposition pathway for either of the two components dioxolane and dimethoxyethane, respectively. These results demonstrate that the capacity fading of a lithium-sulfur cell coincides with the loss of the electrolyte within the cell and there is a strong correlation between the failure of a lithium-sulfur cell and the decomposition reactions of its electrolyte. These findings are supported by a detailed analysis of the gaseous decomposition products after specified cycle numbers. Realistic pouch bag cells are used as test vehicles. Such cells do resemble industrially viable, commercial cells much closer as e.g. coin-type cells: Much lower electrolyte/active mass ratios can be used, thus allowing for a more realistic picture of the failure mechanisms involved.

22 citations


Journal ArticleDOI
Rao Juan1, Xu Runtao1, Tengfei Zhou2, Dawei Zhang1  +1 moreInstitutions (2)
Abstract: Lithium sulfur batteries have been regarded as next-generation battery technology due to its high energy density, environmental benignity and abundance. However, the poor electric/ionic conductivity of sulfur limits the practical use of sulfur in an electrode. The main problem is the high solubility of long-chain polysulfides, which are the intermediates of the electrochemical processes in the liquid electrolyte. The dissolved polysulfide ions shuttle between the cathode and anode, thus causing precipitation of insulating Li 2 S 2 /Li 2 S on the surface of the electrode. The unavoidable phenomenon results in loss of active materials and fast capacity fading. In this regard, we show one simple method to prepare free-standing paper electrode used as cathode material for lithium sulfur batteries. Binder-free graphene-polypyrrole (PPy)/S-graphene (G-PPy/S-G) paper-like sandwich structural electrode was prepared by using the vacuum filtration method. In this structure, the unique graphene layers of sandwich-like framework not only serve as a conductive film, but also effectively block the diffusion of polysulfides, leading to suppression of the shuttle effect and low self-discharge behaviour. In addition, the middle layer, the PPy nanofibers can limit the diffusion of dissolved polysulfides due to the special bond with sulfur, and furthermore maintain the structural stability of the paper electrode because the nanofibers can serve as elastic springs to accommodate the huge volume changes in charging-discharging processes. When tested as cathode for Li-S batteries, the as-prepared sample G-PPy/S-G exhibits excellent electrochemical performance. We believe that our strategy could provide a useful pathway towards commercial utilizing of sulfur.

21 citations


Journal ArticleDOI
Shengtang Liu1, Shengtang Liu2, Li Yaohua1, Li Yaohua2  +8 moreInstitutions (2)
Abstract: Lithium sulfur (Li–S) batteries are regarded as one of the most promising next-generation secondary batteries. However, the insulating nature of active materials, inevitable shuttle effect caused by dissolution of intermediate polysulfides, and severe volume expansion during lithiation prevent their practical application. Herein, we report a novel sulfur host composed of amorphous TiO2 nanofilm interfaces coating on mesoporous carbon by controlling the hydrolytic process of tetrabutyl titanate on the surface of 3D interconnect conductive carbon matrix. The sulfur host shows high surface area, considerable electrolyte wetting capability and strong absorption for lithium polysulfides. Owe to the rational design and outstanding properties, the sulfur cathode with the high active material content of ∼74% and mass loading of ∼3.2 mg cm−2 exhibits a high initial specific capacity of 1455 mAh·g−1 and maintained 1242 mAh·g−1 after 200 cycles at 0.1 C (1C = 1675 mAh·g−1) current density, and also delivers excellent long term cycling performance at 1 C with initial capacity of 720 mAh·g−1 and capacity remained up to 81% after 1000 cycles.

16 citations


References
More filters

Journal ArticleDOI
Abstract: This work reports a quantitative analysis of the shuttle phenomenon in Li/S rechargeable batteries. The work encompasses theoretical models of the charge process, charge and discharge capacity, overcharge protection, thermal effects, self-discharge, and a comparison of simulated and experimental data. The work focused on the features of polysulfide chemistry and polysulfide interaction with the Li anode, a quantitative description of these phenomena, and their application to the development of a high-energy rechargeable battery. The objective is to present experimental evidence that self-discharge, charge-discharge efficiency, charge profile, and overcharge protection are all facets of the same phenomenon.

1,572 citations


Journal ArticleDOI
Abstract: Lithium-ion battery packs in hybrid and pure electric vehicles are always equipped with a battery management system (BMS). The BMS consists of hardware and software for battery management including, among others, algorithms determining battery states. The continuous determination of battery states during operation is called battery monitoring. In this paper, the methods for monitoring of the battery state of charge, capacity, impedance parameters, available power, state of health, and remaining useful life are reviewed with the focus on elaboration of their strengths and weaknesses for the use in on-line BMS applications. To this end, more than 350 sources including scientific and technical literature are studied and the respective approaches are classified in various groups.

672 citations


Journal ArticleDOI
Mark Wild, Laura O'Neill, Teng Zhang1, Rajlakshmi Purkayastha  +3 moreInstitutions (1)
Abstract: Lithium sulfur (Li–S) batteries are one of the most promising next generation battery chemistries with potential to achieve 500–600 W h kg−1 in the next few years. Yet understanding the underlying mechanisms of operation remains a major obstacle to their continued improvement. From a review of a range of analytical studies and physical models, it is clear that experimental understanding is well ahead of state-of-the-art models. Yet this understanding is still hindered by the limitations of available techniques and the implications of experiment and cell design on the mechanism. The mechanisms at the core of physical models for Li–S cells are overly simplistic compared to the latest thinking based upon experimental results, but creating more complicated models will be difficult, due to the lack of and inability to easily measure the necessary parameters. Despite this, there are significant opportunities to improve models with the latest experimentally derived mechanisms. Such models can inform materials research and lead to improved high fidelity models for controls and application engineers.

663 citations


Journal ArticleDOI
TL;DR: It is shown here that consistent progress has been achieved, to the point that this battery is now considered to be near to industrial production, however, the performance of present lithium-sulfur batteries is still far from meeting their real energy density potentiality.
Abstract: This review is an attempt to report the latest development in lithium-sulfur batteries, namely the storage system that, due to its potential energy content, is presently attracting considerable attention both for automotive and stationary storage applications. We show here that consistent progress has been achieved, to the point that this battery is now considered to be near to industrial production. However, the performance of present lithium-sulfur batteries is still far from meeting their real energy density potentiality. Thus, the considerable breakthroughs so far achieved are outlined in this review as the basis for additional R&D, with related important results, which are expected to occur in the next few years.

426 citations


Journal ArticleDOI
Marc Doyle1, John Newman1Institutions (1)
Abstract: Simplified models based on porous electrode theory are used to describe the discharge of rechargeable lithium batteries and derive analytic expressions for the specific capacity against discharge rate in terms of the relevant system parameters. The resulting theoretical expressions are useful for design and optimization purposes and can also be used as a tool for the identification of system limitations from experimental data. Three major cases are considered that are expected to hold for different classes of systems being developed in the lithium battery industry. The first example is a cell with solution phase diffusion limitations for the two extreme cases of a uniform and a completely nonuniform reaction rate distribution in the porous electrode. Next, a discharge dominated by solid phase diffusion limitations inside the insertion electrode particles is analysed. Last, we consider an ohmically-limited cell with no concentration gradients and having an insertion reaction whose open-circuit potential depends linearly on state of charge. The results are applied to a cell of the form Li|solid polymer electrolyte|LiyMn2O4 in order to illustrate their utility.

207 citations


Performance
Metrics
No. of citations received by the Paper in previous years
YearCitations
20214
20204
20194
20183
20175