Lithium metal-polymer

This type of Li battery has already widely diffused in the electronic consumer market, however for automotive applications the presence of a liquid electrolyte is not considered the best solution in terms of safety, then for this type of utilization the so-called lithium polymer batteries appear more convenient. They are based on a polymeric electrolyte which permits the transfer of lithium ions between the electrodes [21]. The anode can be composed either of a lithium metal foil (in this case the device is known as lithium metal polymer battery) or of lithium supported on carbon (lithium ion polymer battery), while the cathode is constituted by an oxide of lithium and other metals, of the same type used in lithium-ion batteries, in which the lithium reversible intercalation can occur. For lithium metal polymer batteries the overall cycling process involves the lithium stripping-deposition at the anode, and the deintercalation-intercalation at the anode, according to the following electrochemical reaction, written for a Mn-based cathode ... 

Carbon/LithiumManganese Oxide Carbon/LithiumNickel Cobalt Oxide Lithium Metal/ Polymer... 

The goal for this battery is to be a substitution for the valve-regulated lead-acid battery (VRLA) as a backup power supply of for telecommunication. Usually, the relay machines of the telecommunication structure are located in remote areas. The VRLA with its short life is inconvenient from a maintenance aspect. Avestor s lithium metal polymer battery drastically reduced the load and cost of the maintenance, because the life of their battery is over 10 years and is maintenance free. Further, the feature of the battery is that the condition of the battery itself can be monitored in remote settings. 

Shin J-H, Henderson WA, Passerini S (2005) PEO-based polymer electrolytes with ionic liquids and their use in lithium metal-polymer electrolyte batteries. J Electrochem Soc 152(5) A978-A983. doi 10.1149/l.1890701... 

All-eleetric vehicles Wh/kg, Wh/L, W/kg, httle or no maintenance (Lead). Lithium-ion. Lithium metal polymer... 

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. 

To begin with (in the mid-1970s ), the positive electrode was made of intercalation materials such as TiS2 (titanium disulfide) whose lamellar structure contained inserted lithium, the negative electrode being made simply of metal lithium, with the difficulties inherent to that electrode, which we shall recap below. These difficulties remain with lithium-metal polymer technology as described in Chapter 8. 

In a lithium-metal polymer battery, the eleetrochemical chain involved is ... 

Figure 8.1. Principle of operation of the lithium-metal polymer battery...

Rechargeable lithium-ion polymer cells incorporate the polymer as part of the electrochemical operation of the battery and these cells are widely used to power such portable consumer products as laptop computers and mobile phones. Lithium-metal-polymer is a relatively new technology from Avestor in Canada. It uses a solid polymeric electrolyte obtained by dissolving a lithium salt in an appropriate co-polymer. The metallic oxide cathode is made from a plastic composite material. 

Lithium-metal-polymer (LMP) is a relatively new technology being promoted by the Canadian Avestor Limited Partnership based in Boucherville, Quebec, for telecommunications applications. Avestor s LMP cell is built up from four elements. An ultra-thin metallic lithium foil anode combines the roles of lithium source and current collector. The solid polymeric electrolyte is made by dissolving a lithium salt in an appropriate co-polymer. The metallic oxide cathode is based on a reversible intercalation compound of vanadium oxide, blended with a lithium salt and a polymer to produce a plastic composite. Finally, an aluminium foil forms the current collector. Avestor cells can operate within the temperature range -40 °C to +65 °C. 

The advantages to the lithium-metal-polymer accumulator are as follows ... 

Lithium-Metal-Polymer Batteries for Electric Auto Applications... 

In particular, in lithium metal polymer batteries, dendritic growth of lithium on a lithium anode, formation of dead lithium, interfacial phenomenon between the lithium anode and the polymer electrolyte, etc., adversely affects the stability and cycle characteristics of the batteries. In view of these problems, various polymer electrolytes have been developed. 

Sivakkumar, S.R., MacEarlane, D.R., Eorsyth, M., and Kim, D.W. (2007) Ionic liquid-based rechargeable lithium metal-polymer cells assembled with polyaniline/carbon nanotube composite cathode. Journal of the Electrochemical Society, 154, A834—A838. 

Avestor spent hundreds of millions of dollars to develop a lithium metal polymer battery, but the company went out of business. The battery used a low-voltage LiV30g positive to stabilize the polymer electrolyte, which consisted of a PE oxide polyether copolymer and hthium perfluorosulfonimide (Li(CF3S0CNS02CF3)). The battery was heated above 40 °C in order to achieve a conductivity of 10 S cm . The battery proved ineffective for use in electric vehicles, but showed some promise in telecommunications applications where cycling was limited. However, even the telecommunications apphcation did not work out. 

Khurana, R., Schaefer, J.L., Archer, L.A., Coates, G.W. 2014. Suppression of lithium dendrite growth using cross-linked polyethylene/poly(ethylene oxide) electrolytes A new approach for practical lithium-metal polymer batteries. T. Am. Chem. Soc. 136 7395-7402. 

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