Li-ion batteries: news, progress, history and background

Unlike dense ceramic coatings applied as a separate layer on competing separators, PPT’s products contain ceramic particles that are thoroughly distributed throughout their chemically inert PVDF polymer. The particles reside primarily in the pore walls, leaving a large and uniform open pore structure that enables ions to pass through with less resistance and less heat generation.  * More power in high-current applications  * Reduced separator shrinkage  * Increased thermal stability with less cell degradation  * Extended cycle life * Higher bake-out and operating temperatures  * Improved puncture and abuse resistance    Although, the application of such separator may improve safety, however according to presented test data it will have minimal effect, or not significant. Depends on battery package, it may have serious explosion (due to electrolyte flammability) at much lower temperature.  

Polypore’s Celgard Files Suit Against Sumitomo Over Batteries - Bloomberg : "" The complaint, filed Feb. 22 in federal court in Charlotte, North Carolina, claims Sumitomo is infringing a patent issued in 2002 for a separator in high-energy rechargeable batteries. The separators prevent short circuits that can reduce efficiency and limit safety problems from overheating. (Via Bloomberg .)

Power bank battery dismantled and reviewed (backup battery for iPho ne produced in China) Before we start some explanation and disclaimer . Here is a short review, based on observations and simple calculation of one of "power bank" or backup battery for iPhone , which may be found in any shop. I did not intend to do this review simply because I did not buy that device and not going to buy such things in a future (ne ar future ). This example device I have got from my frie nd after its stoped working and actu ally the pla s tic shel l become opened (Fig. 2) . This is not a denunciation or exposure for certain product or certain manufacturer or certain country. I hope t his review will make you more skeptical and realistic about what you see and what you get. All dismantle and photos, as well calculation and conclusions done by me.   Although I dismantle Li -ion batteries (LIB) of any shape and size many times for many years since I have work with it for the l...

Hydrocarbon polymer electrolyte membrane (Photo credit: SandiaLabs ) The highly heat-resistant separator coated with Teijinconex meta-aramid The new separator, which is coated with a fluorine-based compound, is designed for use in laminated-type LIBs. Such LIBs, which feature a gel polymer electrolyte, are used in tablets and smartphones. The new separator readily adheres to the polymer electrolyte and is highly resistant to oxidation, resulting in LIBs that offer greater safety, higher output and longer lifespans. The highly heat-resistant separator coated with Teijinconex meta-aramid maintains its shape even at 250℃. In spot heating tests, Teijin has verified that the separator does not break down even at 350℃. Also, thanks to the separator's superior resistance to oxidation, it enables unprecedented capacity and energy density for liquid-electrolyte cylindrical LIBs used in products including PCs and vehicles. These LIBs also achieve higher levels of safety and longer life...

GBL-based electrolyte for Li-ion battery: thermal and electrochemical performance   Journal of Solid State Electrochemistry: Volume 16, Issue 2 (2012), Page 603-615 Thermal stability, flammability, and electrochemical performances of the cyclic carbonate-based electrolytes [where γ-butyrolactone (GBL) is a main component (at least 50 vol.%) among of EC and PC with LiBF 4 ] have been examined in comparison with contemporary (EC/EMC, 1:3 vol.%, 1 M LiPF 6 ) electrolyte by DSC, accelerating rate calorimetry (ARC), AC impedance, and cyclic voltammetry (CV). This study shows that GBL-based electrolytes have perfect thermal stability and will improve Li-ion battery safety (including flammability) without performance trade-off with the accurate combination of active materials and separator. Several types of negative electrode materials (such as hard carbon, MCMB, and SWF) have been tested to evaluate GBL-based electrolyte influence on SEI formation and battery performanc...

New patent application from LG Chem : Provided is an electrochemical device comprising multi-stacked unit cells of full cells or bicells and a separation film disposed therebetween, whereby the separation film and separators are alternately stacked between electrode layers with an opposite polarity. Herein, as the separation film is formed of a material having a higher thermal shrinkage rate than that of the separator, the thermal stability of the device can be secured by stable induction of shutdown via thermal behavior of the separation film, without causing short-circuiting due to thermal shrinkage of the separator even when a temperature of a battery suddenly rises by internal or external factors. Application number: 13/107,122  Publication number: US 2011/0217586 A1 Filing date: May 13, 2011  Inventors: Je Young KIM, Pil Kyu PARK, Soonho AHN Original Assignee: LG CHEM, LTD.   O riginal separator placement New separator placement Also some Claims sug...

Link to presentation

Here are some new testings (overcharge) of Li-ion polymer batteries enjoy video taken from http://www.lithumbattery.com/

New international safety rules agreed for electric cars : "An international safety standard for electric and hybrid vehicles has been adopted this week as the ‘World Forum for Harmonization of Vehicle Regulations’. The adoption of the new type approval clears the way for the early uptake of electric cars across 41 countries which have mutual recognition of this approval. The new regulations cover all [...] " (Via Green cars: latest news .)

1. - Just a joke 2. Really bad - laptop battery explosion 3. Home experiment - soft pack Li-ion battery overcharge 4. Old laptop no the heater plate - frying -> explosion (what you expect?)

It was September 20, 1995 when Apple recalled their new PowerBook 5300 for the first time. The PowerBook 5300 was a big product for Apple. The company had entered into a cross-promotional deal with the producers of Mission Impossible wherein the computer appeared (with a command line interface) throughout the blockbuster movie. Apple was also charging a phenomenal price for the machine, a whopping $6,500 for the 5300ce partly because it was Apple’s first PowerPC-based laptop. The good times didn’t last long. Less than a month after it was introduced, the machine was recalled when preproduction units caught on fire. The problem was blamed on batteries manufactured by Sony, but Apple recalled all the computers sold to that point (claiming that was less than 100 units). The 5300 went on to be recalled again for case problems, but the first recall (and the impetus for a lot of jokes) came this week in 1995 less than a month after the PowerBook 5300 had been released. Source

Here are all news about latest recall

So far, the fields of Li-ion battery application for the last years enlarge and grab increasingly more market from originally discovered - cell phone application to notebooks, digital camera, PDA etc. This is because of their high energy density (smaller size/weight – higher capacity) and the capacity of the Li-ion cells of the same size has increased by > 7% per each year. Now safety is considered one of the most important features of Li-ion cells. Nearly all electricity consumers demand a high voltage, which is realized by connecting cells in series. Since the single cells have different capacities, it is impossible to maintain the optimal charge voltage in the weakest cell at the end of the charge process. Consequently, the cell voltage increases and, besides the main charging reaction, chemical and electrochemical side reactions are possible. To avoid this problem for lithium-ion batteries consisting out of non-over-chargeable cells, computer-controlled charging systems regulat...