tailieunhanh - Lithium-ion Batteries Part 4

Tham khảo tài liệu 'lithium-ion batteries part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 2 Thermo-chemical process associated with lithium cobalt oxide cathode in lithium ion batteries Chil-Hoon Doh and Angathevar Veluchamy Korea Electrotechnology Research Institute Republic of Korea Central ElectrochemicalResearch Institute India 1. Introduction The concept of galvanic couple and the development of battery and fuel cells made possible the direct current DC producing devices for practical applications. Even though existing aqueous electrolyte based power sources such as lead acid nickel metal-hydride nickelcadmium alkaline dry zinc based batteries and magnesium systems reached mature level of technology the lithium based non-aqueous cell system Plitcha et al. 1987 is able to penetrate and steadily expand its market share. Notwithstanding high cost the lithium cells became the candidate of choice for miniature application and also for futuristic power pack for electric vehicle propulsion owing to its light weight high voltage high energy density and low self discharge characteristics. Present day lithium rechargeable cells are constructed usually by coupling a graphite anode and any one of the cathodes among lithium cobaltate LixCoO2 lithium manganese spinel LixMn2O4 Lithium iron phosphate LixFePC 4 Qlivine and lithium Nickelate LixNiO2 in an air tight pouch or in a metal container. Assisted by potential difference between the anode and cathode electricity electrons flows from LiCeQithium intercalated graphite anode to the cathode through an external load accompanying simultaneously Li ion de-intercalation from the anode and intercalation at the cathode maintains charge neutrality in the electrodes for which the electrolyte plays the role of transporting Li ions. 2. Problem description Among the lithium batteries available in the market one with LixCoO2 cathode and graphite anode is acclaimed widely as a source of power for portable electronics. This cell system is considerably stable and provides acceptable calendar cycle life at room temperature .