Pouch Lithium-ion Battery Research Articles

Novel additives-package to mitigate the failure modes of high-capacity LiNi0.82Co0.11Mn0.07O2-based lithium-ion battery

Electrolyte additive strongly influences on energy density and cycle-life of state-of-the-art lithium-ion batteries (LIBs). Without additive, inevitable side reactions at nickel-rich cathode-electrolyte and anode-electrolyte interfaces result in non-satisfactory solid electrolyte interphase (SEI) formation and performance failure due to metal-dissolution from cathode particularly under multiply harsh condition of high voltages and temperatures. Herein, we report the design of a novel additives-package comprising of lithium borate, fluorinated anhydride and fluorinated phosphate at ≤1 wt% for a LIB with markedly improved capacity and performance. We show the synergy effects of individual additive in forming robust SEI layers at both 82% nickel (NCM-82) cathode and graphite anode under 4.35 V, 45 °C and 1C rate by compensating one’s lacking role(s) by others’. Failure modes of NCM-82 chemistry LIBs such as high-voltage instability, metal-dissolution and cracks, surface and structural instability are mitigated, enabling high-capacity of 210 mAh g−1 and high capacity retention of 94% after 100 cycles, with respect to reference electrolyte. Moreover, long cycle-life of 300 cycles of single-layer Li-ion pouch cell at 2C and 100 cycles of industrial pouch LIB (45 mAh cm−2) at 1C is achieved. Our design strategy for additives-package offers a promising path to long-cycled high-energy LIBs.

The effect of using non-Newtonian nanofluid on pressure drop and heat transfer in a capillary cooling system connected to a pouch lithium-ion battery connected to a solar system

The flow of non-Newtonian nanofluids (NNFs) within a lithium-ion battery coupled to a solar cooling system (Li-iBCS) is investigated in this paper. A capillary Li-iBCS is put on the anode and cathode of a pouch lithium battery, which is made up of three pieces. A constant velocity and temperature water-CMC/CuO NNFs flow enters the system and departs after cooling the cathode and anode surfaces. The flow of the NNFs is laminar, and the governing equation for the NNFs and batteries is solved using the finite element technique. According to the research, increasing the fluid velocity in the Li-iBCS reduces the battery average temperature and causes the fluid to leave at a lower temperature. Furthermore, the FOM and heat transfer coefficient are increased when the volume % of nanoparticles (NPs) is increased and the average battery temperature is reduced. The maximum amount of FOM (1.36) occurs at a velocity of 0.1 m/s and a volume percentage (VOPs) of 3%. The minimum amount of FOM (1.01) takes place at velocity of 0.5 m/s and VOP of 0.5%.

Temperature characterization based state-of-charge estimation for pouch lithium-ion battery

Pouch lithium-ion batteries have aroused widespread attention in the field of electric vehicles because of the high energy density and low internal resistance. The available capacity of the battery varies greatly under different temperatures, resulting significant error in state-of-charge (SOC) estimation. An effective approach to relieve this issue is to make full use of the battery surface temperature. This article presents an enhanced Coulomb counting method based on surface temperature characterization to improve SOC estimation accuracy. Theoretical analysis and visualization tests using infrared thermal imager are conducted to identify surface temperature features during battery operation. The feature regions of the pouch lithium-ion battery are initially determined by temperature distribution function and further screened by dynamic time warping (DTW) algorithm. Finally, the screened temperature features are applied to battery available capacity modeling. The experimental results prove that the proposed method can effectively improve the SOC estimation accuracy under various temperature conditions.

Structural integrity of lithium-ion pouch battery subjected to three-point bending

The role of pouch battery configurations in structural integrity under bending loads was investigated using finite elements and compared with experiments. Three-point bending tests were firstly conducted for different pouch battery configurations to obtain force–displacement curves. A finite element model of the pouch battery under the three-point bending was then simulated employing a homogenization technique to reduce the simulation cost and time consumption significantly. Force-displacement curves from the simulation results were extracted and validated by the curve obtained from the bending tests. The validation allowed detailed analysis of stress distribution and deformation inside the pouch battery model. Regions in which short circuits might occur were then identified. The role of folded configuration and pouch casing to resist flexural damage was confirmed by structural strength improvement of 14 and 30 times, respectively. These results may be used for design consideration on safer pouch batteries.

Experimental Investigation on Pouch Lithium-ion Battery Thermal Management with Mini-Channels Cooling Plate Based on Heat Generation Characteristic

Experimental Investigation on Pouch Lithium-ion Battery Thermal Management with Mini-Channels Cooling Plate Based on Heat Generation Characteristic

Thermal characteristics of thermal runaway for pouch lithium-ion battery with different state of charges under various ambient pressures

Aerial vehicles powered by lithium-ion battery (LIB) goes through various ambient pressures. Considering the influence of ambient pressure (p) on the thermal characteristics of pouch battery during thermal runaway (TR), a series of experiments are performed to study the thermal characteristics of TR for commercial pouch LIBs with different state of charges (SOC) under various pressures. Based on the thermal analysis and experiment investigation, the thermal contribution of decomposition energy (Qd) and oxidation combustion energy (Qco) to peak battery temperature Tmax in TR is established. It is found that Tmax is determined by Qd and directly proportional to Qd, as well as affected by Qco. Sufficient concentration of O2 and ratio of combustible emitted gases are the necessary for high values of Qco. Besides, Qco increases in direct proportion to both p and SOC, and it leads to the increase of Tmax through the heat feedback. The area distribution model of TR hazards under various SOCs and pressure conditions is also established, and it can be used for evaluating and predicting the TR hazards under various conditions. Moreover, some mitigation measures and suggestions LIB safety and the decrease of TR hazards are proposed.

Characterization of in-situ material properties of pouch lithium-ion batteries in tension from three-point bending tests

To understand the mechanisms of deformation and failure of lithium-ion batteries in case of a crash, it is necessary to accurately characterize their constitutive properties. Previous studies in the field mainly focused on the homogenized compression properties of the cells, which are dominant in load cases such as local indentations. However, in complex practical loadings, such as bending, tension properties play an equally important role. Such complex loads can lead to rupture of the electrode tabs and external short-circuits, which can cause catastrophic outcomes. In the current literature, tensile properties are characterized using specimens extracted from the cell, outside of their operational environment, which leads to unrealistic values. In this study, for the first time, an analytical characterization method is developed to extract the homogenized tensile properties of a cell from bending tests in in-situ conditions. In the next step, this data is used, along with an elaborative procedure, to calibrate a fully uncoupled anisotropic material model for the pouch cells. The material model is utilized to build a single homogenized finite element pouch cell model which is the first of its kind to be validated in all major loading cases; flat, hemispherical, and cylindrical punch indentations and specifically three-point bending, and in-plane compression. This material characterization and the modeling approach provide a universal tool in predicting the load-displacement, shape of deformation, buckling wavelength, and the trend of failure in complex crash scenarios for the safety assessments of Lithium-ion batteries.

Tab Design for Thermal Reduction in Pouch Lithium-Ion Battery by Using Finite Element Method

Tabs are important sections of receiving and transmitting electrical power to various equipment. However, if the internal temperature of the battery is too high, the battery getting too hot may shorten the battery life and lose its original performance. Therefore, to troubleshoot this device from overheating, there is necessary to design the suitable tabs. In this work, the developed finite element method is employed to simulate the temperature distribution of 3.65 V/20 Ah pouch battery at the C-rate of 1C, 3C, and 5C. The simulated results appear that a significant heat accumulation at the positive tab of Li-ion battery will occur when the highest discharge rate of 5C is conducted. Also, the high rate of this discharge makes the cell core of battery have a higher temperature as well. Therefore, the thermal behavior is further analyzed by adjusting the sizes of tabs, i.e., height, thickness, and width. As a result of size modifications, a reduction in the heat deposition and current density are observed. In addition, the received results also show that the tab with dimensions of 20 mm ( 0.35 mm ( 54 mm (height, thickness, and width, respectively) is the suitable size for diminishing the average temperature of the tab and cell core as well as increasing a distribution to be uniform. Regarding the temperature change, the sizes mentioned above can drop its temperature by 6.68 °C for tab and 2.03 °C for cell core as compared to the original case.

Spontaneous nanominiaturization of silicon microparticles with structural stability as flexible anodes for lithium ion batteries

Silicon (Si) is an ideal anode material for lithium ion batteries (LIBs) because of its high gravimetric capacity (3579 mAh g−1). However, Si anode undergoes sharp volume expansion during the charge/discharge process and then easily fragments to forfeit electronic contact, thereby forming dead Si, especially for micron-sized Si particles. We prepared a free-standing Si-based film anode, in which the micron Si particles are embedded by a coupled network of carbon nanotubes and the micro-nano structure is anchored by a carbon nanocoating layer. The networks can catch the nanominiaturized Si particles and provide continuous electrical contact during long cycling, thereby reviving the fragmented Si and maintaining lithium storage properties. This Si anode exhibits an ultra-high specific capacity of 3385.2 mAh g−1. The excellent cycling performance of 2345.3 mAh g−1 remained after 100 cycles at a current density of 0.3 A g−1. The pouch LIB based on the Si anode showed outstanding rate capacity and flexibility. This strategy is expected to solve the volume expansion and promote the application of the micron Si-based materials.

Thermal Safety and Runaway Blocking Mechanism for Lithium-Ion Batteries through Introducing Nanoscale Magnesium Hydroxide into the LiNi0.5Co0.2Mn0.3O2 Cathode

The thermal safety of pouch lithium-ion batteries (LIBs) with a nominal capacity of 2000 mA h is improved by adding nanoscale Mg(OH)2 into the LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode, and the thermal ...

Effect of mechanical extrusion force on thermal runaway of lithium-ion batteries caused by flat heating

The thermal runaway (TR) of lithium-ion batteries (LIBs) hinders the development of new energy vehicles (NEVs) because its extrusion-state characteristics remain unclear. Here, 100% state of charge (SOC) pouch LIBs are heated under extrusion, for triggering TR. The battery temperature, voltage, and deformation during the TR are recorded, and a high-speed infrared camera is used along with a high-definition camera for capturing the TR's flame evolution process. The battery thickness gradually decreases with increasing the temperature of a squeezed-state battery, until dropping abruptly at the TR onset. In the squeezed state, smoke is produced for a shorter time, the TR jet intensity significantly increases, and the wreckage exhibits a tight block structure. The TR onset occurs faster for higher squeezing pressures, the jet fire duration is shorter, while the flame temperature and area increase. The maximal temperature of the battery surface increases first and then drops, and the mechanism of the TR gradually changes from heating to internal circuit shorting. For squeezing pressures under 5000 N, the TR onset temperature increases slightly compare with the non-squeezed state, and then decreases to approximately 100 °C as the pressure approaches 5000 N.

Predicting anisotropic thermophysical properties and spatially distributed heat generation rates in pouch lithium-ion batteries

This paper proposes a novel thermal characterization approach to determine the specific heat capacity, anisotropic thermal conductivities, and spatially distributed heat generation rates of pouch lithium-ion batteries (LIBs) through a combined experimental and numerical simulation process. Unlike cylindrical LIBs, pouch LIBs subjected to high C-Rates exhibit non-uniform heat generation distributions due to the combined effect of their low impedance, large size, and internal structure. These thermophysical properties and distributed heat generation rates are crucial for designing, modeling, and assessing the performance of pouch-based battery thermal management systems. The proposed thermal characterization approach does not require expensive lab equipment and extensive details of the battery internal structure. Instead, it relies on simple battery experiments integrated with numerical modeling to predict these properties through inverse heat transfer simulations. The characterization approach accounts for non-uniform heat generation distribution through a geometric factor that discretizes the battery volume into three regions, and concentration factors that determine the percentage of the total heat generation rate in each region. Finally, the validation of the characterization approach and its accuracy is assessed with experimental data independent of that used in the characterization process.

Method of Liquid-Cooled Thermal Control to a Large-Scale Pouch Lithium-Ion Battery

Excellent thermal management has the count for much significance in preserving lithium-ion battery cell work-performance and extending cell cycle-life. This work presents a method of thermal control for a large-scale pouch cell by using a liquid cooling plate with streamline channels. Numerically, influences of mass flow rates, cooling trigger-time, and glycol solution concentration on the cell thermal distribution are seriously analyzed. Experimentally, the simulation effectiveness is validated per a constructed thermal test system. It is shown that the increasing mass flow rate acts a positive role in crippling the cell temperature rise and difference, however there having a marginal effect about this condition. Effect of postponing cooling trigger-time on promoting the cell thermal homogeneity is negative, yet the delayed trigger-time can capture an outstanding cost-effectiveness. The maximum cell temperature and channel pressure drop increase with increasing glycol solution concentration. Experimental validation suggests that the test and simulation results coincide well with each other, indicating that a promising availability dwells in present thermal management to manage the cell temperature field under a desirable range. This study would be valuable for one to develop a reliable cooling solution for a battery pack stacked with large-scale pouch cells.

Influence of orientation on ageing of large-size pouch lithium-ion batteries during electric vehicle life

In the electric vehicle (EV) battery packs, large-size lithium-ion pouch batteries (LiBs) are mostly used and to miniaturise the battery pack's volume, some manufacturers put the LiBs in different orientations. It is well established that temperature gradients over large-size LiBs surface cause ageing non-uniformities, but the influence of the LiBs orientation on the ageing has to date received little attention. Here, we present an analysis of orientation influence on the large-size pouch LiB's ageing on eight batteries from two differently orientated modules from the dismantled first-generation Nissan Leaf retired battery pack. The influence of orientation is also analysed for brand-new second-generation Nissan Leaf battery which has almost the same geometry as batteries from the retired pack. By utilising infrared (IR) thermography and electrochemical impedance spectroscopy (EIS) techniques, the influence of orientation on the LiBs ageing non-uniformity is detected. Whilst temperature maps analysis shows different LiBs' thermal behaviour depends on their orientation, EIS measurements show that ageing non-uniformity can be identified by analysing the solid-electrolyte-interphase and charge-transfer resistances. Presented results show that different LiBs orientation in EV battery packs should be avoided because it can cause ageing non-uniformities over the battery surface and their second-life applications should be applied with caution.

Experiment and Simulation for Air-Cooling the Tabs of a Pouch Battery Module with Distributed Resistance Model

A novel distributed electric resistance model is used to describe the heat generation characteristics of a cell with the electric resistance of a cell is divided into three parts: the main body, two current collectors, and two electrode tabs. This model was used to simulate the effects of natural convection cooling and forced air convection cooling on tabs of a lithium-ion pouch battery, and the effects of dry air and wet air on the cooling effect. The parameter of the module cooling coefficient (MCC) was introduced to evaluate the effect of thermal management. The results show that wet air has a better cooling effect than dry air, but the cooling effect of wet air with 15% and 75% relative humidity is almost the same, and increasing the inlet air velocity can significantly improve the cooling effect. In addition, the index MCC of positive and negative tabs and the heat flux during cooling process are quantified, so as to provide better service for thermal management design.

Numerical optimization of the cooling effect of the bionic spider-web channel cold plate on a pouch lithium-ion battery

For lithium-ion battery thermal management system for electric vehicles, the insertion of metal plates with channels on both sides of a lithium-ion battery is an effective method for a high-temperature cooling. Inspired by the nature spider-web structure, we propose a cold plate with a bionic spider-web channel inside. Based on the heat generation characteristics of the pouch lithium-ion battery at an extreme discharge rate of 12 C, we used an orthogonal experimental design to study the cooling performance of the spider web-channel structure for a lithium-ion battery. Numerical simulation results showed that, among the structural parameters of the spider-web channel, the channel width had the largest influence on the cooling performance of the cold plate, while the channel angle had the smallest influence. The increase in the channel width could not indefinitely enhance the cooling performance of the cold plate. The most suitable structure was obtained at a width of 3 mm. When the channel angle was 120°, the pouch lithium-ion battery could provide the best thermal balance.

Thermal management of a 48 V pouch lithium-ion battery pack based on high rate discharge condition

Thermal management of a 48 V pouch lithium-ion battery pack based on high rate discharge condition

The Anisotropic Homogenized Model for Pouch Type Lithium-Ion Battery Under Various Abuse Loadings

Abstract Pouch type lithium-ion battery (LIB) has now been widely used in electric vehicles, smartphones, and computers. Mechanical abuse is one of the main reasons to cause the safety issues for lithium-ion battery. The highly accurate and efficient computational model is helpful for the safety design, application, and analysis of LIB. The previous homogenized mechanical models of the pouch LIB use different material parameters for various loading conditions. Herein, we establish an anisotropic homogenized method to predict the mechanical behavior in in-plane and out-of-plane directions simultaneously. Engineering constants and Hill's 48 criteria are used for the anisotropic properties, and bilinear plastic model is used as the hardening curve under large deformation. On the basis of this method, we established two homogenized models, i.e., one-layer model and multilayer model. Experiments in various loading conditions including three-point bending (length direction and width direction), out-of-plane compression, and in-plane compression (length direction and width direction) are conducted for parameters calibration. The calibration methods are then discussed and confirmed through these experiments. The computational models show good correlation with experiments in both in-plane and out-of-plane directions. The difference is that the global buckling behavior can be predicted by both of the two models, while the local buckling can be predicted only by the multilayer model. The results may shield light on the safety design, application, and analysis for pouch LIB.

Detection and recognition of batteries on X-Ray images of waste electrical and electronic equipment using deep learning

The trend of increased use of lithium-ion batteries, challenges the cost-effectiveness and safety of manual battery separation during the end-of-life treatment of Waste Electric and Electronic Equipment (WEEE). Therefore, the need for novel techniques to separate and sort batteries from WEEE is increasingly important. For this reason, the presented research investigates the potential to facilitate the development of novel techniques for battery extraction and sorting by examining the technical feasibility of predicting the presence, location, and type of batteries inside electronic devices with a deep learning object detection network using X-Ray images of the internal structure of WEEE. To determine the required X-ray imaging parameters, 532 electronic devices were arbitrarily collected from a recycling facility. From each product, two X-Ray Transmission (XRT) images were captured at two different X-Ray source configurations. Results obtained with the limited dataset are promising, demonstrating a 91% true positive rate and only a 6% false positive rate for classifying battery-containing devices. Moreover, a precision of 89% and a recall of 81% are demonstrated for battery detection, and an average precision of 85% and an average recall of 76% are demonstrated to distinguish amongst the following six battery technologies: cylindrical nickel-metal hydride or nickel-cadmium, cylindrical alkaline, cylindrical zinc-carbon, cylindrical lithium-ion, pouch lithium-ion, and button cell batteries. These results demonstrate the potential of using deep learning object detection on XRT-generated images for both automated battery extraction and sorting, regardless of the condition or shape of the products.

Applications of different nano-sized conductive materials in high energy density pouch type lithium ion batteries

Lots of lithium ion battery (LIB) products contain lithium metal oxide LiNi5Co2Mn3O2 (LNCM) as positive electrode active material. To increase the conductivity, conductive carbon-based materials including acetylene black and carbon black become necessarily consisted in electrodes. Recently, carbon nano-tube (CNT) appears as a popular choice for conductive carbon in LIB. However, a large quantity of the conductive carbon which cannot provide capacity as the active material will decrease the energy density of batteries. The ultra-high cost of CNT comparing to conventional carbon black is also a problem. In this work, we are going to introduce ‘short length’ and ‘long length’ carbon nano-tube (S-CNT and L-CNT) into electrode in order to design a reduced-amount conductive carbon electrode. The whole experiment will be done in 1 Ah commercial type pouch LIB. By decreasing conductive carbon as well as increasing the active material in positive electrode, the energy density of LNCM-based 1Ah pouch type LIBs with only 0.16% of L-CNT inside LNCM positive electrode could reach 224 Wh/kg and 549 Wh/L, in weight and volume energy density, respectively. Also, this high energy density LIB with L-CNT reveals stable cyclability may become a valuable progress in portable devices and electric vehicle (EV) applications.