Scientists at Stanford University and the Department of Energy's SLAC National Accelerator Laboratory have created a self-healing battery electrode, which could help pave the way toward more robust high-capacity batteries for electric vehicles and portable electronics.
The electrode was made by combining silicon microparticles -- a promising, but fragile, high-capacity battery material -- with self-healing polymers that seal the cracks that typically form when a battery is used and recharged (see figure and video below). The electrode has eight times the storage capacity of conventional lithium battery carbon anodes and can currently withstand 100 charging cycles - 10 times that of previous silicon batteries.
Cracks formed in a self-healing silicon electrode due to swelling during charging (top) begin to seal back up within hours (bottom).
(Source: C. Wang et al, Nature Chemistry)
A personal hydroelectric generator, called the Hydrobee, is currently seeking funding on Kickstarter. The device consists of a mini hydropower turbine in a can with six AA rechargeable batteries and a USB port (see figure below), and is designed to provide a renewable USB power source for mobile electronics users with access to flowing water, either from a stream or river or a water faucet. Charging time is two to four hours depending on water flow rate and pressure.
A cutaway view of the Hydrobee personal hydropower turbine in a can.
Research firm EnergyTrend is predicting that prices for cylindrical lithium ion batteries will decline by about 2.8% in 2014. The downtrend is attributed to high-capacity lithium polymer battery supply crowd out and thinner consumer electronics, as well as increased competition in the medium-to-high capacity (~2.8 to 3.0 Ah) battery market segment. (See "New Era Approaches as Gross Margin and Quantity of Lithium Battery Decrease.")
In product news, Linear Technology introduced a triple-output DC/DC controller designed to drive three strings of LEDs. The LT3797 has a 2.5 to 40-V input range and a rail-to-rail LED current sense range of 0 to 100 V.
A load switch series from Toshiba Electronics is offered as having the industry's lowest on-resistance - 18.4 mΩ at an input voltage of 0.75 V. The TCK20xG has output current handling to 2A and typical standby and quiescent currents of 1 µA and 20 µA, respectively.
Test equipment manufacturer Megger announced a rugged, handheld, battery-operated transformer turns ratio tester. The TTR20 measures the turns ratio, excitation current and polarity of windings in single- and three-phase distribution and power transformers (tested phase by phase), potential and current transformers, and tapped transformers.
Finally, UK-based Accutronics has launched a new range of pre-qualified and pre-tested 14.4-V lithium ion batteries targeting medical device design applications. The customizable VR420 batteries are available in 4.4- and 6.2-Ah versions, and include an SMBus, SBS-compliant impedance tracking fuel gauge.