The Lithium-ion Battery Electrochemical Performance Test System And Its Application Research

Because of the rise of serious environmental pollution and energy crisis, the development and application of new energy has become more and more vital. Whereas the tremendous recent progress in the lithium-ion battery, it has been of great concern in the research of new energy field due to its high performances such as high voltage, high energy density, long cycle life and environmental friendliness. Based on those advantages of lithium-ion battery, it has been widely used in the areas of portable electronic product, electric bicycle and energy storage equipment. As the further development of lithium-ion battery, a higher request to improve the quality and performance of lithium-ion battery has been put forward. The development of battery materials and the innovation of its technics craft are the main ways to enhance the performance and quality of batteries. Moreover, the battery test system play an extremely important role in the study of the battery.In order to promote lithium-ion battery development and meet the high quality test requirements in battery researches, this paper designs a state-of-the-art multi-channel high precision Lithium-ion battery test system, which mainly consists of charge-discharge test modules, data acquisition module, internal resistance detection module, expanding circuit module and data communication modular.By researching the charge-discharge test method of battery, a high-precision constant current power, which based on MOSFET and controlled by closed-loop feedback, has been designed in this paper,because it can realize programmable control of constant-current charging, constant-current discharging and constant-voltage charging. In order to satisfy requirement of battery testing under different conditions and improve the versatility of test system, this paper presents a multi-range, high-precision current acquisition method, which can realize multigrade, high precision constant current output and multigrade, high precision current acquisition, and then make the test system can be used for battery products research and test, also can be used for battery materials research and analysis. Beside that, the internal resistance of battery is difficult to measure online, this paper presents a novel method to detect battery internal resistance online by phase-locked amplifier technology to extract weak signal. It offers a way to research battery internal resistance under specific conditions.Aim to improving the test system precision and assuring high reliable operation, this article described the methods of noise suppression from the designing of hardware and software respectively. To verify the performance and reliability of test system, it does some tests for the lithium battery. By analyzing the test data such as constant current output value, current, voltage, internal resistance, the result indicates that the test system has high precision and high reliability.The test system is a multi-task real-time master-slave control system and its control process is very intricacy. According to the Top-down principle, this paper adopte modularization and hierarchical model during designing software, and the final test system software is integrated by all function blocks. This kind software design method is convenient for the management and program modification during the whole software development, which is also easy to the function expansion and upgrade. The test system software is composed by embedded software and upper computer software. The embedded software is programmed through C programming language to realize survey control and data acquisition, and the upper computer software using LabVIEW to realize human-computer interaction, master-slave control, data processing and analysis.The development of high-performance batteries is ultimately dependent on the electrode materials. From the practice of application in research of cathode material, this paper researches the synthesizing condition of the high performance materials, which are used as new electrodes for lithium-ion batteries, with the help of the existing test conditions. NbOx has drawn special attention in electrochemical lithium storage due to its stable cycling. NbOx@C nanoparticles are synthesized through the oleyamine-mediated hydrolysis of niobium (V) chloride under solvothermal conditions, combined by annealing technique. When tested as anode materials, the result indicates the lithium storage properties of NbOx@C are much better than those of NbOx, because of the fact that carbon component improved the electric conductivity. Due to its high theoretical capacity, NiO has become one of the most promising electrodes materials, but some nanostructured NiO electrodes displayed undesired cycling performance. This paper fabricats the a-Ni(OH)2microspheres by a hydrothermal method. They are annealed at different temperatures(450,600and750℃), the corresponding NiO samples could be obtained. When tested as anode materials, the NiO-600and NiO-750electrodes display excellent cycling performances due to their linked nanoparticle networks, It should be noted that the structural characteristics of electrode materials played more important roles in determining the cycling performance. Transition-metal oxides have attracted much attention because of their higher reversible capacities. There are few reports on applying Mn2O3as anode materialforlithium-ionbatteries. The porous one-dimensional Mn2O3nanostructures are synthesized via a facile hydrothermal treatment and sequential thermal decomposition. Experimental results show that as a demonstration of potential applications for lithium-ion batteries anode materials, the polycrystalline porous Mn2O3nanostructures exhibited a large initial discharge capacity and relative poor cycle performance. The present porous one-dimensional Mn2O3structures show a potential application in lithium ion batteries.