Research on the Influence of Stray Parameters in the Circuit of the Hybrid Energy Storage
In the course of battery discharge in hybrid energy storage, overvoltage trends to appear at opposite ends of the IGBT (Insulated Gate Bipolar Transistor) when the IGBT is switched off, which is likely to cause overvoltage to damage the IGBT. To solve the problem, this paper has made analyses of the mechanism of capacitor when overvoltage caused by the IGBT failure, the stray inductance in the hybrid energy storage circuit and the inductance of switch-off current on the overvoltage. And the corresponding mathematical formula is derived. On the basis, a simulation model is established. The rational distribution and the addition of an absorption loop can reduce the peak value of overvoltage. It is found from simulations that the absorption circuit will lead to voltage oscillation in the main circuit. Aimed at this phenomenon, the design of the absorption loop is optimized. Simulations and experiments prove the proposed method to be effective.
Research on high rate discharge for lithium ion battery
This paper researched on high rate discharge performance in lithium ion battery. Battery design influenced on the high rate discharge performance sincerely, then a new design about lithium ion battery came forth. The electrode material ingredient, surface density and thickness of electrode were researched. This paper found a favorable high rate discharge performance lithium ion battery, which had high discharge capacity, flat voltage, preferable cycle performance and low temperature when discharging. A rule on discharge capacity was found, and a charge and discharge system for high rate discharge lithium ion battery was recommended.
A New Class of Electrochemically and Thermally Stable Lithium Salts for Lithium Battery Electrolytes IV. Investigations of the Electrochemical Oxidation of Lithium Organoborates
Synthesis, analysis, and purification of lithium bis[2,2'-biphenyldiolato(2-)-O,O']borate, lithium bis[salicylato(2-)]-borate, lithium phenolate, and dilithium-2,2'-biphenyldiolate are described. Electrochemical studies show that lithium organoborates are subject to anodic decomposition mechanisms, which depend on their chemical structure. The anodic decomposition of lithium benzenediolatoborates results in the formation of soluble products including chinones, whereas the anodic oxidation of lithium bis[2,2'-biphenyldiolato(2-)-O,O']borate, lithium bis[salicylato(2-)]borate, and lithium phenolates entails the formation of thin electronically insulating lithium ion-conducting polymer films, preventing further anion decomposition as well as anodic decomposition of solvents which are sensitive to oxidation. These film-forming materials are useful to enlarge the electrochemical window of electrolyte solutions for lithium batteries and electrochemical capacitors.