Polymer lithium secondary batteries

Lithium secondary batteries can be classified into three types, a liquid type battery using liquid electrolytes, a gel type battery using gel electrolytes mixed with polymer and liquid, and a solid type battery using polymer electrolytes. The types of separators used in different types of secondary lithium batteries are shown in Table 1. The liquid lithium-ion cell uses microporous polyolefin separators while the gel polymer lithium-ion cells either use a PVdF separator (e.g. PLION cells) or PVdF coated microporous polyolefin separators. The PLION cells use PVdF loaded with silica and plasticizer as separator. The microporous structure is formed by removing the plasticizer and then filling with liquid electrolyte. They are also characterized as plasticized electrolyte. In solid polymer lithium-ion cells, the solid electrolyte acts as both electrolyte and separator. 

Because of the importance of high-performance secondary batteries, the techniques of the secondary lithium batteries are still making rapid progresses. Lithium polymer secondary batteries, having gel-polymer electrolytes, are advantageous in that the rigid metal container is not essential. Thus, all-plastic thin lithium secondary batteries are now available. 

The molecular orbital (MO) calculations within the PM3 method, using a MOP AC package, provided an explanation of the advantages of a new redox system, poly(l,4-phenylene-l,2,4-dithiazolium-3, 5 -yl) (PPDTA), as a cathode material for high-capacity lithium secondary batteries in comparison with three typical polymer conductors (poly-/>-phenylene, polypyrrole, and polythiophene). The MO calculation revealed that the S-S bond in the 1,2,4-dithiazo-lium moiety of PPDTA caused gap narrowing and a downshift of HOMO and LUMO levels, which is consistent with the electrochemical experiment (HOMO = highest occupied molecular orbital LUMO = lowest unoccupied molecular orbital) <2001MI2305>. 

Ion conducting polymers may be preferable in these devices electrolytes because of their flexibility, moldability, easy fabrication and chemical stability (for the same reasons that they have been applied to lithium secondary batteries [19,48,49]). The gel electrolyte systems, which consist of a polymeric matrix, organic solvent (plasticizer) and supporting electrolyte, show high ionic conductivity about 10 5 S cnr1 at ambient temperature and have sufficient mechanical strength [5,7,50,51], Therefore, the gel electrolyte systems are superior to solid polymer electrolytes and organic solvent-based electrolytes as batteries and capacitor materials for ambient temperature operation. 

Conductive polymers as electrodes Table 5.1 Theoretical performances for some lithium secondary batteries ... 

In this chapter, lithium secondary batteries using conductive polymers as positive electrodes are discussed with particular attention to the charge-discharge characteristics, discharge capacity, self-discharge, cycling life and so on. 

Figure 5.1 shows various conductive polymers studied as electrodes for lithium secondary batteries. 

Nishio, K., et al. 1991. Characteristics of a lithium secondary battery using chemically synthesized conducting polymers. J Power Sources 34 153. 

Solid polymer electrolytes have been actively pursued as a major contribution to the development of high-energy density batteries, particularly lithium secondary batteries. The poly(p-phenylene)s substituted with oligo(oxymethylene) side chains and blends of these novel polymers with lithium salts are achieved by biaryl coupling of benzene-1,4-diboronic acids (Fig. 4). ° OctapoIy(p-phenylene) functions as the artificial ion channel which specially recognizes (bio)membranes by their thickness (Fig. 5). ... 

Novak, P., Inganas, O., and BJorklund, R., Composite polymer positive electrode in solid state lithium secondary batteries, J. Electrochem. Soc., 134, 1341-1345 (1987). 

The chemical products involved in the charge and discharge reactions constitute active material. For lithium secondary batteries, the active matter is contained in the electrode we speak of positive active matter at the positive electrode and negative active matter at the negative electrode. For instance metal oxide at the positive and graphite at the negative for a lithium-ion element, or transition metal oxide at the positive and metal lithium at the negative for a lithium metal polymer cell. 

Park KS, Sehougaard SB, Goodenough JB (2007) Conducting-polymer/iron-redox-couple eomposite eathodes for lithium secondary batteries. Adv Mater 19(6) 848-851... 

Oyama N (2000) Development of polymer-based lithium secondary battery. Macromol Symp 159(l) 221-228... 

In order to manufacture a composite polymer electrolyte for a lithium secondary battery, a copolymer of vinylidene fluoride and hexafluoropropylene is casted with an conducting inorganic filler. 

Y.G. Lee, K.M. Kim, K.S. R5m, and S.H. Chang, Lithium cationic single-ion conducting filler-containing composite polymer electrolyte for lithium secondary battery and metiiod of manufacturing the same, US Patent 7 399 556, assigned to Electronics and Telecommunications Research Institute (Daejeon, KR), July 15,2008. 

Li M, Wang L, Yang B, Du T, Zhang Y (2014) Facile preparation of polymer electrolytes based on the polymerized ionic liquid poly((4-vinylbenzyl)trimethylammonium bis(trifluoro methanesulfonyUmide)) for lithium secondary batteries. Electrochim Acta 123 296-302. doi 10.1016/j.electacta.2013.12.179... 

The majority of electrochemical cells to have been constructed are based on PEO, PAN, or PVdF [101]. Recently, the Yuasa Corporation have commercialized solid polymer electrolyte batteries, primarily for use in devices such as smart cards, ID cards, etc. To date, the batteries which have been manufactured and marketed are primary lithium batteries based on a plasticized polymer electrolyte, but a similar secondary battery is expected [120]. 

E—Lithium Lithium anode Iodine, sulfur dioxide, thionyl chloride, and iron disulfide Secondary Lithium-iron disulfide batteries, lithium-ion batteries, and lithium polymer batteries... 

More recently, solid state batteries with lithium conducting polymer electrolytes have been extensively studied. The development has focused on secondary batteries for an electric vehicle, because lithium polymer batteries have a theoretical energy density that approaches 800 W h kg ... 

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