Sodium polystyrene sulfonate (or polystyrene sulfonic acid) is a type of polymer and ionomer based on polystyrene. The polyanion is readily soluble in water, and insoluble in lower alcohols. The solid appears as white or off-white powder. It may be prepared by polymerization or copolymerization of sodium styrene sulfonate or by sulfonation of polystyrene. The harsh conditions used in this procedure lead to the occurrence of a number of side reactions. Double substitutions of the phenyl rings are known to occur, even with conversions well below 100%. Crosslinking reactions are also found, where condensation of two sulfonic acid groups yield a sulfonyl crosslink. On the other hand, the use of milder conditions such as acetyl sulfate leads to incomplete sulfonation. Recently, the ATRP (Atom transfer Radical Polymerization) of protected styrenesulfonates has been reported, leading to well defined linear polymers, as well as more complicated molecular architectures.
Sodium polystyrene sulfonate is used as a superplastifier in cement, crosslinked polystyrenes that are then sulfonated have found widespread use in ion-exchange applications, it is used as a dye improving agent for cotton and as proton exchange membranes in fuel cell applications.
Lithium-ion batteries (sometimes abbreviated Li-ion batteries) are a type of rechargeable battery in which a lithium ion moves between the anode and cathode. The lithium ion moves from the anode to the cathode during discharge and from the cathode to the anode when charging.
Lithium ion batteries are commonly used in consumer electronics. They are currently one of the most popular types of battery for portable electronics, with one of the best energy-to-weight ratios, no memory effect, and a slow loss of charge when not in use. In addition to uses for consumer electronics, lithium-ion batteries are growing in popularity for defense, automotive, and aerospace applications due to their high energy density. However certain kinds of mistreatment may cause Li-ion batteries to explode.
The three primary functional components of a lithium ion battery are the anode, cathode, and electrolyte, for which a variety of materials may be used. Commercially, the most popular material for the anode is graphite. The cathode is generally one of three materials: a layered oxide, such as lithium cobalt oxide, one based on a polyanion, such as lithium iron phosphate, or a spinel, such as lithium manganese oxide, although materials such as TiS2 (titanium disulfide) were originally used. Depending on the choice of material for the anode, cathode, and electrolyte the voltage, capacity, life, and safety of a lithium ion battery can change dramatically. Lithium ion batteries are not to be confused with lithium batteries, the key difference being that lithium batteries are primary batteries containing metallic lithium while lithium-ion batteries are secondary batteries containing an intercalation anode material.
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