Thermal modelling of commercial lithium-ion batteries

The accelerating adoption of electrical technologies in vehicles over the recent years has led to an increase in the research on electrochemical energy storage systems, which are among the key elements in these technologies. The application of electrochemical energy storage systems for instance in hybrid electrical vehicles (HEVs) or hybrid mobile working machines allows tolerating high power peaks, leading to an opportunity to downsize the internal combustion engine and reduce fuel consumption, and therefore, CO2 and other emissions. Further, the application of electrochemical energy storage systems provides an option of kinetic and potential energy recuperation. Presently, the lithium-ion (Li-ion) battery is considered the most suitable electrochemical energy storage type in HEVs and hybrid mobile working machines. However, the intensive operating cycle produces high heat losses in the Li-ion battery, which increase its operating temperature. The Li-ion battery operation at high temperatures accelerates the ageing of the battery, and in the worst case, may lead to a thermal runaway and fire. Therefore, an appropriate Li-ion battery cooling system should be provided for the temperature control in applications such as HEVs and mobile working machines. In this doctoral dissertation, methods are presented to set up a thermal model of a single Li-ion cell and a more complex battery module, which can be used if full information about the battery chemistry is not available. In addition, a non-destructive method is developed for the cell thermal characterization, which allows to measure the thermal parameters at different states of charge and in different points of cell surface. The proposed models and the cell thermal characterization method have been verified by experimental measurements. The minimization of high thermal non-uniformity, which was detected in the pouch cell during its operation with a high C-rate current, was analysed by applying a simplified pouch cell 3D thermal model. In the analysis, heat pipes were incorporated into the pouch cell cooling system, and an optimization algorithm was generated for the estimation of the optimalplacement of heat pipes in the pouch cell cooling system. An analysis of the application of heat pipes to the pouch cell cooling system shows that heat pipes significantly decrease the temperature non-uniformity on the cell surface, and therefore, heat pipes were recommended for the enhancement of the pouch cell cooling system.

Determination of the thermal parameters of high-power batteries by local heat

A new approach to the determination of the thermal parameters of high-power batteries is introduced here. Application of local heat flux measurement with a gradient heat flux sensor (GHFS) allows determination of the cell thermal parameters in di_erent surface points of the cell. The suggested methodology is not cell destructive as it does not require deep discharge of the cell or application of any charge/discharge cycles during measurements of the thermal parameters of the cell. The complete procedure is demonstrated on a high-power Li-ion pouch cell, and it is verified on a sample with well-known thermal parameters. A comparison of the experimental results with conventional thermal characterization methods shows an acceptably low error. The dependence of the cell thermal parameters on state of charge (SoC) and measurement points on the surface was studied by the proposed measurement approach.

Carta particolare della Gronlandia orientale : la longitudine comincia da l'isola di Pico d'Asores [i.e. Pico Azores] : di Europa carta LI

Julkaisussa: Dell' arcano del mare di Ruberto Dudleo ... parte seconda del tomo terzo contenente il libro sesto. Vol III

Questa e la perfetta et vera descrittione et il vero disegno et sito del Mare Adriatico, di Larcipelago, del Mare di Soria, et del Mare Egeo, con li nomi volgari che hoggidi Seusano da Italiani, de l'Isole, Scogli, Capi, Golfi, Porti, et luochi che in ditti mari se ritruovano à o de l'Isole quanto delle infrascritte Prouicie di tema ferma, cioè di Bytinia, Misia, Licia, e Cilicia, del Peloponneso detto Morea, de l'Albania, et della Dalmatia, con la maggior parte dell'Italia, descritte secondo che in le carte da navigar se co[n]tegono

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Tre canzoni nelle parole di Li-Tai-Pe

Soitinnus: lauluääni, piano.

Apply of energy storages in electricity distribution networks and reserve capacity applications

The Thesis is dedicated to development of an operative tool to support decision making of battery energy storages implementation in distribution networks. The basics of various battery technologies, their perspectives and challenges are represented in the Thesis. Mathematical equations that describe economic effect from battery energy storage installation are offered. The main factors that influence profitability of battery settings have been explored and mathematically defined. Mathematical model and principal trends of battery storage profitability under an impact of the major factors are determined. The meaning of annual net value was introduced to show the difference between savings and required costs. The model gives a clear vision for dependencies between annual net value and main factors. Proposals for optimal network and battery characteristics are suggested.

De veritate occulta, Psalm. LI. 8

Invokaatio: I.N.J.