Li-Ion Rechargeable Batteries
Li-Ion (Lithium-Ion) batteries are the most common rechargeable batteries in portable electronics. Lithium ion batteries have one of the best energy densities, no memory effect,  slow loss of charge when not in use and environmentally safe because there is no free lithium metal, in comparison with other types of rechargeable batteries. Rechargeable lithium ion batteries are the preferred compact light weight storage media of choice to store a large amount of energy in a small space. They provide power for electric cars, electric bicycles, smart phones and laptops. Globally researchers are currently in the process of developing new generation of such batteries with an improved performance. In most lithium ion batteries these days, the plus pole is composed of the transition metal oxides cobalt, nickel, and manganese, the minus pole of graphite. In more powerful lithium ion batteries of the next generation, however, elements such as tin or silicon may well be used at the minus pole.
Nanomaterial based lithium ion batteries
Researchers from the Laboratory of Inorganic Chemistry at ETH Zurich and Empa have now developed a nanomaterial based lithium ion batteries.
Structure
The nanomaterial has tiny tin crystals as the battery anode. During charging lithium ions get absorbed at this electrode and released again while discharging. With more lithium ions the electrodes can absorb and release and hence more energy can be stored in the battery. Here each tin atom can absorb at least four lithium ions, but change in volume. In the tin electrodes tin crystals become up to three times bigger by absorbing a lot of lithium ions and shrinks again when it releases them back which is a challenge to the researchers. If the electrode were made of a compact tin block, this would practically be impossible. To overcome this drawback researchers use nanotechnology to produce the tiniest and uniform tin nanocrystals and embed a large number of them in a porous, conductive permeable carbon matrix.
During the development of the nanomaterial with ideal size and uniformity the researchers follow two steps during formation of small crystal nucleus and its subsequent growth by influencing the time and temperature of the growth phase.
Future development
With the choice of the best possible carbon matrix and binding agent for the electrodes, and an ideal microscopic structure for electrodes along with an optimal and stable electrolyte liquid in which the lithium ions can travel back and forth between the two poles the researcher believe that cost-effective base materials suitable for electrode production with increased energy storage capacity and lifespan can be produced.