Lithium-ion Battery Energy Storage Research Articles

Techno-economic analysis of the viability of residential photovoltaic systems using lithium-ion batteries for energy storage in the United Kingdom

Rooftop photovoltaic systems integrated with lithium-ion battery storage are a promising route for the decarbonisation of the UK’s power sector. From a consumer perspective, the financial benefits of lower utility costs and the potential of a financial return through providing grid services is a strong incentive to invest in PV-battery systems. Although battery storage is generally considered an effective means for reducing the energy mismatch between photovoltaic supply and building demand, it remains unclear when and under which conditions battery storage can be profitably operated within residential photovoltaic systems. This fact is particularly pertinent when battery degradation is considered within the decision framework. In this work, a commercially available coupled photovoltaic lithium-ion battery system is installed within a mid-sized UK family home. Photovoltaic energy generation and household electricity demand is recorded for more than one year. A comprehensive battery degradation model based on long-term ageing data collected from more than fifty long-term degradation experiments on commercial Lithium-ion batteries is developed. The comprehensive model accounts for all established modes of degradation including calendar ageing, capacity throughput, ambient temperature, state of charge, depth of discharge and current rate. The model is validated using cycling data and exhibited an average maximum transient error of 7.4% in capacity loss estimates and 7.3% in resistance rise estimates for over ayear of cycling. The battery ageing model is used to estimate the cost of battery degradation associated with cycling the battery according to the power profile logged from the residential property. A detailed cost-benefit analysis using the data collected from the property and the battery degradation model shows that, in terms of utility savings and export revenue, the integration of a battery yields no added benefit. This result was, in-part, attributed to the relatively basic control strategy and efficiency of the system. Furthermore, when the cost of battery degradation is included, the homeowner is subject to a significant financial loss.

Model-Based Dispatch Strategies for Lithium-Ion Battery Energy Storage Applied to Pay-as-Bid Markets for Secondary Reserve

Due to their decreasing cost, lithium-ion batteries (LiB) are becoming increasingly attractive for grid-scale applications. In this paper, we investigate the use of LiB for providing secondary reserve and show how the achieved cost savings could be increased by using model-based optimization techniques. In particular, we compare a maximum use dispatch strategy with two different cost-minimizing strategies. For the estimation of state-dependent battery usage cost, we combine an existing electro-thermal LiB model of a mature lithium-iron-phosphate battery cell with corresponding semiempirical calendar and cycle aging models. We estimate the benefit of storage operation from the system operator's point of view by gauging the avoided cost of activated reserve. Our evaluation is based on two years worth of data from the German reserve market. The proposed cost minimizing dispatch strategies yield significantly better results than a dispatch strategy that maximizes battery utilization.

Operation of a Grid-Connected Lithium-Ion Battery Energy Storage System for Primary Frequency Regulation: A Battery Lifetime Perspective

Because of their characteristics, which have been continuously improved during the last years, Lithium-ion batteries have been proposed as an alternative viable solution to present fast-reacting conventional generating units to deliver the primary frequency regulation service. However, even though there are worldwide demonstration projects, where energy storage systems based on Lithium-ion batteries are evaluated for such applications, the field experience is still very limited. In consequence, at present, there are no very clear requirements on how the Lithium-ion battery energy storage systems should be operated, while providing frequency regulation service and how the system has to reestablish its state of charge (SOC) once the frequency event has passed. Therefore, this paper aims to investigate the effect on the lifetime of the Lithium-ion batteries energy storage system of various strategies for reestablishing the batteries’ SOC after the primary frequency regulation is successfully delivered.

Development of a Rep-Rated Pulsed Power System Utilizing Electrochemical Prime Power

The U.S. Naval Research Laboratory is developing a rep-rate charger for a 60-kJ capacitor module. The charger is lithium-ion battery powered and must charge up the capacitive load 50 times over a 5-min period with roughly 1 s between each charge cycle. This paper examines some aspects of the design: lithium-ion battery energy storage, hard switched dc–dc converter, high-voltage rectifier, and capacitive load with pulsed power switching. The lithium-ion batteries are arranged in 12, 16-cell, 50 V modules that are connected in series to form a roughly 600 V prime power supply. A hard switched dc–dc converter with full-bridge rectifier is used to charge the capacitor and a pulse forming network is used to discharge the capacitor into the load. This paper will discuss the system design and available test data.

Nonlinear predictive energy management of residential buildings with photovoltaics & batteries

This paper studies a nonlinear predictive energy management strategy for a residential building with a rooftop photovoltaic (PV) system and second-life lithium-ion battery energy storage. A key novelty of this manuscript is closing the gap between building energy management formulations, advanced load forecasting techniques, and nonlinear battery/PV models. Additionally, we focus on the fundamental trade-off between lithium-ion battery aging and economic performance in energy management. The energy management problem is formulated as a model predictive controller (MPC). Simulation results demonstrate that the proposed control scheme achieves 96%-98% of the optimal performance given perfect forecasts over a long-term horizon. Moreover, the rate of battery capacity loss can be reduced by 25% with negligible losses in economic performance, through an appropriate cost function formulation.

Grid connected performance of a household lithium-ion battery energy storage system

Lithium-ion Battery Energy Storage Systems (BESS) are to be the next household electrical appliance in a smart grid environment. This is beside the growth of electrical vehicles with lithium-ion batteries. However, these batteries are yet to prove their performances in the household sector.This paper presents the performances of a small household scale battery energy storage system with a lithium-ion battery pack and a single-phase ac-dc inverter. Results of a list of tests conducted in a lab environment are presented explaining the test procedures and results.Test results show that the considered BESS is suitable for daily cycling applications but has low efficiencies at the rated power operations. Converter losses contribute to the low efficiency of the considered BESS. The BESS is more efficient in lower power (lower than rated) operations. However, the effects of the current harmonics need to be considered when it is operated with other appliances.

Amorphous Bimetallic Co3Sn2Nanoalloys Are Better Than Crystalline Counterparts for Sodium Storage

Sodium-ion batteries are considered as a promising alternative to replace the existing lithium-ion batteries for energy storage due to the benefits of low cost and safety. However, it is still challenging to develop suitable electrode materials for reversible storage of sodium. Metal anodes have high capacity for sodium storage but suffer the issue of poor cyclability due to pulverization caused by large volume variation and electrode disintegration. To address this issue, amorphous bimetallic active–inactive nanoalloy Co–Sn with Sn acting as a high capacity active compound and Co acting as a conductive inactive matrix has been explored here. We demonstrated that amorphous nanoalloys exhibited superior electrochemical performances as compared to the low-crystalline and crystalline counterpart nanoalloys as negative electrode materials for sodium-ion batteries. The degree of crystallinity has negative effects on electrochemical performances. The improved performance of amorphous nanoalloys could be attribu...

전기추진선박의 전력품질 개선을 위한 리튬-이온 배터리 에너지저장시스템 적용

This paper explained the application of a lithium-ion battery energy storage system to electric propulsion ships. The power distribution in electric propulsion ships has low power quality because of the variation in the power consumption of the propulsion motor. For proper operation of the ship, the power quality needs to be improved, and the battery energy storage system is used to solve power-quality problems. The simulation models of electric propulsion ship and battery energy storage systems are constructed on MATLAB/Simulink to verify the improvement in power quality. The proposed system is applied in various scenarios of the propulsion motor state. The power quality achieved by using the battery energy storage system in both voltage and frequency satisfies the standards set by IEC-60092/101.

Energy Analysis of a Real Grid Connected Lithium Battery Energy Storage System

Today, in the grid there are more and more installation of renewable energy plants. The renewable sources are so discontinues and they may affect the stability and efficiency of the grid. Many distribution service operators are experimenting the battery energy storage systems (BESSs) to integrate them on the grid and resolve these problems. This paper analyses the energy performance under real conditions of a BESS prototype. The real BESS under focus has made by a lithium battery pack of 16 kWh, a DC/DC converter of 20 kW and an IGBT inverter of 30 kVA with a direct voltage bus of 600 V. The energy analysis has been performed through an integrated data acquisition system that take data from on-board electronic diagnostic measurements and from smart metering data. This latter using remote devices. The tests have been carried out on the system to monitor the following characteristic parameters: current and voltage of the batteries, current and voltage of the grid and current and voltage of the auxiliaries. The system energy performances have been analyzed in dynamic and real conditions with particular reference to the following quantities: energy consumption for the auxiliary system and overall efficiency of the system in a distributed energy resources microgrid. The entire system has been analyzed until twenty-four hours.

Lithium-Ion Battery Energy Storage Systems for Grid Applications

The use of storage devices to support grid functions is seen as a viable option to meet an increasing electricity demand. Simulations performed will provide a look into the sustainability and life of a lithium-ion battery in continuous operation that can be used to support on-grid services. Specifically, COMSOL Multiphysics will be used to model a lithium manganese oxide battery and illustrate the capacity fade, solid-electrolyte interphase (SEI) formation leading to potential drop and electrolyte potential drop in the battery. These simulations will provide insight into continuous cycling phenomena of charging and discharging a battery.

Heterostructure of SnO2/TiO2 Nanotubes with Precise Wall Thickness Control As Anodes for Lithium Ion Battery

Devices of energy storage and conversion draw much attention recently, among the devices, secondary lithium-ion batteries for energy storage will play an increasingly important role. SnO2 as anode materials have attracted a lot of attention and are regarded as one of the most promising candidates for lithium-ion battery, with the theoretical reversible capacity of 782 mAhg- 1 and low enough discharge potential of 0.01V. Like to other alloy-type anode materials, its practical application has been impeded by the poor cycling performance owing to the pulverization and subsequent electrical disconnection of the electrode caused by extremely large volume change (about 300%) during the insertion and extraction processes of lithium ions. Li2O phases, produced by the reaction of SnO2 and lithium ions, are electrochemically inactive, which is the main reason for the large initial irreversible capacity. To overcome this problem, feasible strategy is to design the nanostructure. 1-dimensional nanotubular structures exhibit enhanced cyclability due to the short diffusion path of lithium ions within the wall of nanotubes and the local empty space in the core of tubular structures can accommodate its volume expansion. SnO2 and TiO2 nanotubes as well as their heterostructures were synthesized by anodic aluminum oxide (AAO) template-directed ALD (Atomic Layer Deposition) process. Nanotubes and their heterostructures were characterized by thermogravimetric/differential thermal analysis (TG/DTA), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The wall thickness of nonotubes can be easily controlled by the number of cycles during ALD processes. The porous nanotubes and their heterostructures exhibit high lithium ion storage capacity, fairly high rate performance, and high cyclability when evaluated as anode materials. As expected, the nanotubes of SnO2 with the wall thickness of about 10 nm show the initial capacity of 900 mAhg-1 and reduces down to 300 mAhg-1 after 50 cycle. The conversion reaction of SnO2 to Sn and further Li and Sn alloys were clealy observed by ex sity TEM. Composite heterostructures of TiO2/SnO2 show much improved cycle performance without any degradation during Li insertion and di-insertion. Advantages of using heterostructure of TiO2/SnO2 nanotubes as anode materials will be further discussed. Figure 1

Electrochemically active, crystalline, mesoporous covalent organic frameworks on carbon nanotubes for synergistic lithium-ion battery energy storage

Organic batteries free of toxic metal species could lead to a new generation of consumer energy storage devices that are safe and environmentally benign. However, the conventional organic electrodes remain problematic because of their structural instability, slow ion-diffusion dynamics, and poor electrical conductivity. Here, we report on the development of a redox-active, crystalline, mesoporous covalent organic framework (COF) on carbon nanotubes for use as electrodes; the electrode stability is enhanced by the covalent network, the ion transport is facilitated by the open meso-channels, and the electron conductivity is boosted by the carbon nanotube wires. These effects work synergistically for the storage of energy and provide lithium-ion batteries with high efficiency, robust cycle stability, and high rate capability. Our results suggest that redox-active COFs on conducting carbons could serve as a unique platform for energy storage and may facilitate the design of new organic electrodes for high-performance and environmentally benign battery devices.

Coordinated Control of Isolated Microgrid Including Wind Power, Storage and Seawater Desalination Load

The establishment of isolated microgrid including wind power, storage and seawater desalination load is of significant important to the use of renewable energy and the supply of fresh water resources in island region. A real-time simulation platform based on PXI and PC is built to test the operation and control of the isolated microgrid in this paper. The digital simulation model is introduced and the coordinated control strategy of the microgrid is discussed in detail. This strategy makes use of the controllability of seawater desalination load, coordinates supercapacitor and lithium-ion battery energy storage so as to maintain the balance and stability of the isolated microgrid. Finally, the simulation results show that the correctness and feasibility of the proposed coordinated control strategy.

Field Experience from Li-Ion BESS Delivering Primary Frequency Regulation in the Danish Energy Market

In this paper it is presented the practical experience from operating a 1.6 MW/ 0.4 MWh lithium ion battery energy storage system, which is providing primary frequency regulation service on the Danish energy market. Aspects of the battery system requirements and the used control strategy for primary frequency regulation service are discussed. Moreover, the estimation of the battery storage system lifetime is discussed based on the results from 1.5 years periodic inspections and measured performance degradation of the both BESSs.

Porous carbon-coated silica macroparticles as anode materials for lithium ion batteries: Effect of boric acid

We report carbon-coated porous silica macroparticles (SiO2@C) prepared using polymeric templates and subsequent carbonization with sucrose for improved electrochemical energy storage in lithium-ion batteries (LIBs). In addition, boron is introduced to improve the stability of electrochemical cells by pyrolyzing mixtures of sucrose and boric acid (SiO2@C + B) under inert atmosphere. The initially large surface area of porous SiO2 (SBET ∼ 658 m2 g−1) is reduced to 102 m2 g−1 after carbonization and introduction of boric acid. Surface of both SiO2@C and SiO2@C + B are covered with amorphous carbon. In particular, SiO2@C + B particles containing borosilicate (Si–O–B) phase and B–O bondings and Si–C–O bondings are also detected from the X-ray photoelectron spectra. The SiO2@C + B macroparticles shows high reversible charge capacity up to 503 mAh g−1 after 103 cycles of Li intercalation/de-intercalation although initial capacity was 200 mAh g−1. The improved charge capacity of SiO2@C + B is attributed to formation of advantageous microstructures induced from boric acid.

Lithium titanate hybridized with trace amount of graphene used as an anode for a high rate lithium ion battery

A novel Li4Ti5O12 (LTO) electrode with a hierarchical carbon-based conducting network has been developed for high rate lithium ion battery. The unique network is constructed by graphene sheets (GS) that are not only dispersed among (inter-) but also inside (intra-) LTO particles, together with a thin carbon layer wrapping around the LTO particles. The intraparticle GS promotes the electron transfer inside LTO particles while the interparticle GS together with carbon coating bridges the particles guaranteeing fast electron transfer among LTO particles, which construct a highway throughout the whole electrode sheet. Quantitatively, only a trace amount of GS (∼ 0.4 wt%) synergistic with carbon coating (∼0.8 wt%) contributes to a more effective conducting network in the produced LTO electrode and as a result much better performance as compared to the LTO case with similar carbon coating but free of GS. Due to the effectiveness of the conducting network, even with a tap density as high as ∼1.0gcm−3, the novel LTO possesses both excellent rate performance and cycling behaviors. The capacity of 123.5mA h g−1 is obtained at a charge/discharge rate as high as 30C and a very high capacity of 144.8 mAh g−1 is maintained even after 100 cycles at 10C. Due to such a low fraction of carbon and a high tape density, the novel LTO electrode has a great practical application value in both the power and energy storage lithium ion batteries.

Multi-objective optimal design of lithium-ion battery packs based on evolutionary algorithms

Lithium-battery energy storage systems (LiBESS) are increasingly being used on electric mobility and stationary applications. Despite its increasing use and improvements of the technology there are still challenges associated with cost reduction, increasing lifetime and capacity, and higher safety. A correct battery thermal management system (BTMS) design is critical to achieve these goals. In this paper, a general framework for obtaining optimal BTMS designs is proposed. Due to the trade-off between the BTMS's design goals and the complex modeling of thermal response inside the battery pack, this paper proposes to solve this problem using a novel Multi-Objective Particle Swarm Optimization (MOPSO) approach. A theoretical case of a module with 6 cells and a real case of a pack used in a Solar Race Car are presented. The results show the capabilities of the proposal methodology, in which improved designs for battery packs are obtained.

Single Crystal Nuclear Magnetic Resonance Studies of LiMnxFe1-XPO4

LiMPO4 are orthorhombic crystals, belonging to the olivine family and exhibit exceptionally high applicability for electrochemical energy storage in lithium-ion secondary batteries due to their charge storage capacity, chemical and thermal stability, and cost. Furthermore, mixed transition metal ion compounds Li(M,M’)PO4 are particularly promising cathode materials because the redox voltage increases as from Fe to Mn, Ni, Co 1and the mixed compounds can be tailored for specific applications.The aim of these studies is to better understand the key role played by the transition metals such as Fe, Mn and particularly their mixtures in determining the properties of these materials. Single crystal 7Li and 31P NMR studies are used to obtain precise information on the magnetic environments of the lithium ions and phosphate groups which may ultimately be correlated with processes and structural features that determine the electrochemical behavior of these olivine phosphates.By measurements of 7Li and 31P NMR frequencies, i.e. ν = B0∙σ∙Ι, where B0 is the applied field and Ι is the nuclear spin, with crystal orientation, it is possible to determine interaction tensor components {σij } giving rise to the lithium and phosphorus shifts. The series of the single crystals of LiMPO4 were prepared by a reciprocal salt flux growth technique, which allows the facile preparation of single crystals up to 1 cm across with well-developed facets at relatively low temperatures. Crystals for the NMR measurements present their natural faceting2.X-ray diffraction measurements were performed in order to identify the principal crystallographic axes [100], [010] and [001] of the samples. Subsequently the crystals were fixed to a rigid insert in the NMR probe, which was mounted onto a goniometer and inserted between the gap of a permanent magnet (B0=2.1T). The use of a relatively low field strength allowed for acquisition of the entire rotation pattern within the spectrometer bandwidth. Rotations were made with the goniometer shaft perpendicular to applied magnetic field, in this way it was possible to generate 24 spectra, one every 15o, for each crystallographic axis [100],[010] and [001].Previous studies3 showed that in the case of 31P, crystals exhibit large (paramagnetic) shifts on the order of 3000ppm, primarily due to the hyperfine interactions between the unpaired electron spins of the paramagnetic ion and the phosphorus nuclei.The 7Li resonances are also strongly affected by the paramagnetic susceptibility though not to the same extent as 31P. However in addition, there is a nuclear quadrupole interaction which splits the resonance and provides information concerning the electric field gradientIn addition to the endpoints (Fe and Mn analogues), we present an NMR analysis of the mixed transition metal ion compounds LiFexMn1-xPO4 , where x = 0.25, 0.5, and 0.75 in order to shed some light on the degree of cation disorder between the lithium, phosphorus, and transition metal sites that can result in substantial degradation of cathode performance particularly with regard to reduced rate capability.This research was supported by the U.S. Department of Energy

Development and Testing of Four-Wheel Drive In-Wheel-Motor Electric Vehicle

This paper describes the development of a full electric vehicle prototype with a new generation of drive-by-wire chassis, which consists of a four independently actuated in-wheel-motor drive system, an electric power steering (EPS) system, an electro-hydraulic brake (EHB) system and a lithium battery energy storage system. This novel electric vehicle called I2EV (I2 stands for Intelligent and In-wheel-motor) is designed and tested on a chassis dynamometer to study its performance. Then the road performance of the vehicle is verified through road experiments. These tests clearly show that I2EVcan be employed in further study of intelligent vehicle and advanced integrated chassis control.

NextEnergy Center’s Highlights on Global Lithium Ion Battery Supply Chain Dynamics and Domestic Opportunities

Lithium ion batteries are utilized in a range of applications including grid support and powering consumer electronics, medical devices, and electric vehicles. Advocacy for, as well as public and private investment in hybrid cars and electric vehicles has resulted in a surge in research and development (R&D) to create more powerful and cost effective lithium ion batteries. This high level of interest has also led to rapid expansion of battery manufacture capacity and has resulted in the over-capacity and fragmentation of the industry. Due to the disjointed quality of the lithium-ion battery industry, opportunities for collaboration and growth, resulting from numerous innovations throughout the supply chain, are overlooked. [1] Although range anxiety is often portrayed as the primary reason electric vehicle adoption is not growing more rapidly by the general population, the cost of vehicles is actually the larger issue. At present, the battery pack is the highest cost component driving the price of EVs. A year-long study was conducted by NextEnergy to obtain a better understanding of the size, scope, and supply chain dynamics of the lithium ion battery and next-generation energy storage systems industries. One major objective of the study was to better understand and define areas of opportunity for cost reduction, the results of which are presented in this paper.