battery Related Articles

Engineers at the University of Maryland have invented an entirely new kind of battery. It is bio-compatible because it produces the same kind of ion-based electrical energy used by humans and other living things.In our bodies, flowing ions (sodium, potassium and other electrolytes) are the electrical signals that power the brain and control the rhythm of the heart, the movement of muscles, and much more. In traditional batteries, the electrical energy, or current, flows in form of moving electrons. This current of electrons out of the battery is generated within the battery by moving positive ions from one end (electrode) of a battery to the other. The new UMD battery does the opposite. It moves electrons around in the device to deliver energy that is a flow of ions. This is the first time that an ionic current-generating battery has been invented. "My intention is for ionic systems to interface with human systems," said Liangbing Hu, the head of the group that developed that battery. Hu is a professor of materials science at the University of Maryland, College Park. He is also a member of the University of Maryland Energy Research Center and a principal investigator of the Nanostructures for Electrical Energy Storage Energy Frontier Research Center, sponsored by the Department of Energy, which funded the study. "So I came up with the reverse design of a battery," Hu said. "In a typical battery, electrons flow through wires to interface electronics, and ions flow through the battery separator. In our reverse design, a traditional battery is electronically shorted (that means electrons are flowing through the metal wires). Then ions have to flow through the outside ionic cables. In this case, the ions in the ionic cable -- here, grass fibers -- can interface with living systems." The work of Hu and his colleagues was published in the July 24 issue of Nature Communications. "Potential applications might include the development of the next generation of devices to micro-manipulate neuronal activities and interactions that can prevent and/or treat such medical problems as Alzheimer's disease and depression," said group member Jianhua Zhang, PhD, a staff scientist at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health in Bethesda, Md. "The battery could be used to develop medical devices for the disabled, or for more efficient drug and gene delivery tools in both research and clinical settings, as a way to more precisely treat cancers and other medical diseases, said Zhang, who performed biological experiments to test that the new battery successfully transmitted current to living cells.. "Looking far ahead on the scientific horizon, one hopes also that this invention may help to establish the possibility of direct machine and human communication," he said. Bio-compatible, bio-material batteries Because living cells work on ionic current and existing batteries provide an electronic current, scientists have previously tried to figure out how to create biocompatibility between these two by patching an electronic current into an ionic current. The problem with this approach is that electronic current needs to reach a certain voltage to jump the gap between electronic systems and ionic systems. However, in living systems ionic currents flow at a very low voltage. Thus, with an electronic-to-ionic patch the induced current would be too high to run, say, a brain or a muscle. This problem could be eliminated by using ionic current batteries, which could be run at any voltage. The new UMD battery also has another unusual feature -- it uses grass to store its energy. To make the battery, the team soaked blades of Kentucky bluegrass in lithium salt solution. The channels that once moved nutrients up and down the grass blade were ideal conduits to hold the solution. The demonstration battery the research team created looks like two glass tubes with a blade of grass inside, each connected by a thin metal wire at the top. The wire is where the electrons flow through to move from one end of the battery to the other as the stored energy slowly discharges. At the other end of each glass tube is a metal tip through which the ionic current flows. The researchers proved that the ionic current is flowing by touching the ends of the battery to either end of a lithium-soaked cotton string, with a dot of blue-dyed copper ions in the middle. Caught up in the ionic current, the copper moved along the string toward the negatively charged pole, just as the researchers predicted. "The microchannels in the grass can hold the salt solution, making them a stable ionic conductor," said Chengwei Wang, first author of the paper and a graduate student in the Materials Science and Engineering department at the University of Maryland in College Park. However, the team plans to diversify the types of ionic current electron batteries they can produce. "We are developing multiple ionic conductors with cellulose, hydrogels and polymers," said Wang. This is not the first time UMD scientists have tested natural materials in new uses. Hu and his team previously have been studying cellulose and plant materials for electronic batteries, creating a battery and a supercapacitor out of wood and a battery from a leaf. They also have created transparent wood as a potentially more energy-efficient replacement for glass windows. Creative Work Ping Liu, an associate professor in nanoengineering at the University of California, San Diego, who was not involved with the study, said: "The work is very creative and its main value is in delivering ionic flow to bio systems without posing other dangers to them. Eventually, the impact of the work really resides in whether smaller and more biocompatible junction materials can be found that then interface with cells and organisms more directly and efficiently." Source:University of Maryland Ref.ML-621S/ZTNMS412FE-FL26E  

When you hear the word battery, what do you think? Those annoying pink Duracell rabbits, the ones you have stolen from the back of the remote control or the fact that your phone’s battery may as well cease to exist because nowadays it barely lasts all of five minutes? It is a common fear in most of us, that whilst we are out having a good time your phone’s battery is quickly fading in your pocket. However, we never seem worried about the battery’s eventual lifespan, which for the record is normally between three and five years. There are in fact ways to keep your battery in pristine condition for a long and powerful life; even though batteries do not enjoy eternal life. Many smartphone manufacturers insist that devices rate batteries at 300-500 cycles, which isn’t necessarily good news for us. Apple claims that its laptop batteries reach 80% of their original capacity after just 1,000 charges. After this point batteries aren’t able to hold as much electricity and will power your device for increasingly shorter periods of time. Whilst you taken on all this negative battery news fear not; let’s take a look at some tips to extend your battery’s lifespan, whether that is an iPhone, Android phone, Windows phone, tablet, or laptop. Let’s start with something that is on everyone’s minds – the big question; when re-charging a battery should you let it run to zero before charging full to 100%? One reason why people are unsure is something they’ve heard of called the battery ‘memory effect’. What is battery memory effect?Battery memory effect is about batteries remembering remaining charge if you don’t let them go all the way to zero too often. So a battery frequently charged from 20-80% might ‘forget’ about the 40% that’s left uncharged (0-20% and 80-100%). Sounds like a bit of an old wives tale? Well it sort of is true, but only for older nickel-based (NiMH and NiCd) batteries, not the lithium-ion batteries in your phones now. Fortunately for us, Lithium-ion (Li-ion) batteries don’t suffer the memory effect so you basically what is best for them is the total opposite; charge them often but not all the way throughout the day, and don’t let them drop to zero. Don’t charge your phone battery from zero to 100%The golden rule with Li-ion batteries is to keep them 50% or more most of the time, so when it drops below 50% if you can just top it up a little bit. ‘Little and often’ as they say a few times a day seems to be the optimum to aim for. But ideally don’t charge it all the way to 100%. It won’t be fatal to your battery if you do fully recharge, I mean most of us are forced to do this every now and again in an emergency, but constantly doing a full recharge will shorten the battery’s lifespan. So a good range to aim for when charging a Li-ion battery is from about 40-80% in one go. Try not to let the battery drop below 20%. When should I do a full battery charge?Experts recommend that you do a full zero to 100% battery recharge, or as they call it a ‘charge cycle’ maybe once a month only. This is so the battery can recalibrate - a bit like restarting your computer, or, for humans, going on holiday and relaxing. Another top tip; the same rule applies to laptops. Should I charge my phone overnight?Most modern smartphones are clever enough to stop charging when full, so there isn't a great risk in leaving your phone charging overnight. However some experts have recommended you remove the phone from a case if charging for a long time, as a case could lead to over-heating. This is what Lithium-ion batteries do not like. Should I use fast battery charging?Many Android phones have a feature that allows for fast charging, often referred to as Qualcomm Quick Charge or, in Samsung's case, Adaptive Fast Charging. These phones have special code usually located in a chip known as the Power Management IC (PMIC) that communicates with the charger you are using and requests that it send power at a higher voltage. However, unfortunately for the Apple lovers out there, the iPhone 6 doesn’t feature fast charging, but its Qualcomm PMIC is smart enough to recognise when you use a higher-amp charger (like the one you get with the iPad), which is a good thing because fast charging will heat up that Li-ion battery and cause it increased wear and tear. For this exact reason, phones shouldn’t be left in a hot car, on the beach or next to the oven. Overheating the battery will suffer long-term effects on its lifespan and on the other hand so will a super-cold one, so don’t leave your device in the freezer or out in the snow. If you can, switch off fast charging on your Android phone. Can I use any charger?It is best to use your charger, so where possible use the charger that came with your phone, as it is sure to have the correct rating. Or make sure that a third-party charger is approved by your phone's manufacturer. Cheap alternatives from Amazon or eBay may harm your phone, and there have been several reported cases of cheap chargers actually catching on fire. Storing battery tipsDon’t leave a Li-ion battery li-ing around too long at 0%. Try to leave it at around 40-50%. These batteries drain at about 5-10% a month when not in use. So if you let your battery discharge completely and leave it uncharged for a long period of time it may eventually become incapable of holding a charge at all – RIP it’s officially dead. It’s unlikely you’ll leave your smartphone lying in a drawer for very long, but think about laptops, battery packs or spare batteries that are unused for long periods of time. So try to keep them all at least half charged. Ref.ML-621S/ZTNML-614S/FN

Electrical engineers at the University of California San Diego have developed a temperature sensor that runs on only 113 picowatts of power -- 628 times lower power than the state of the art and about 10 billion times smaller than a watt. This near-zero-power temperature sensor could extend the battery life of wearable or implantable devices that monitor body temperature, smart home monitoring systems, Internet of Things devices and environmental monitoring systems.   The technology could also enable a new class of devices that can be powered by harvesting energy from low-power sources, such as the body or the surrounding environment, researchers said. The work was published in Scientific Reports on June 30.   "Our vision is to make wearable devices that are so unobtrusive, so invisible that users are virtually unaware that they're wearing their wearables, making them 'unawearables.' Our new near-zero-power technology could one day eliminate the need to ever change or recharge a battery," said Patrick Mercier, an electrical engineering professor at UC San Diego Jacobs School of Engineering and the study's senior author.   "We're building systems that have such low power requirements that they could potentially run for years on just a tiny battery," said Hui Wang, an electrical engineering Ph.D. student in Mercier's lab and the first author of the study.   Building ultra-low power, miniaturized electronic devices is the theme of Mercier's Energy-Efficient Microsystems lab at UC San Diego. Mercier also serves as co-director for the Center for Wearable Sensors at UC San Diego. A big part of his group's work focuses on boosting energy efficiencies of individual parts of an integrated circuit in order to reduce the power requirement of the system as a whole.   One example is the temperature sensor found in healthcare devices or smart thermostats. While the power requirement of state-of-the-art temperature sensors has been reduced to as low as tens of nanowatts, the one developed by Mercier's group runs on just 113 picowatts -- 628 times lower power.   Minimizing power   Their new approach involves minimizing power in two domains: the current source and the conversion of temperature to a digital readout.   Researchers built an ultra-low power current source using what are called "gate leakage" transistors -- transistors in which tiny levels of current leak through the electronic barrier, or the gate. Transistors typically have a gate that can turn on and off the flow of electrons. But as the size of modern transistors continues to shrink, the gate material becomes so thin that it can no longer block electrons from leaking through -- a phenomenon known as the quantum tunneling effect.   Gate leakage is considered problematic in systems such as microprocessors or precision analog circuits. Here, researchers are taking advantage of it -- they're using these minuscule levels of electron flow to power the circuit.   "Many researchers are trying to get rid of leakage current, but we are exploiting it to build an ultra-low power current source," Hui said.   Using these current sources, researchers developed a less power-hungry way to digitize temperature. This process normally requires passing current through a resistor -- its resistance changes with temperature -- then measuring the resulting voltage, and then converting that voltage to its corresponding temperature using a high power analog to digital converter.   Instead of this conventional process, researchers developed an innovative system to digitize temperature directly and save power. Their system consists of two ultra-low power current sources: one that charges a capacitor in a fixed amount of time regardless of temperature, and one that charges at a rate that varies with temperature -- slower at lower temperatures, faster at higher temperatures.   As the temperature changes, the system adapts so that the temperature-dependent current source charges in the same amount of time as the fixed current source. A built-in digital feedback loop equalizes the charging times by reconnecting the temperature-dependent current source to a capacitor of a different size -- the size of this capacitor is directly proportional to the actual temperature. For example, when the temperature falls, the temperature-dependent current source will charge slower, and the feedback loop compensates by switching to a smaller capacitor, which dictates a particular digital readout.   The temperature sensor is integrated into a small chip measuring 0.15 × 0.15 square millimeters in area. It operates at temperatures ranging from minus 20 C to 40 C. Its performance is fairly comparable to that of the state of the art even at near-zero-power, researchers said. One tradeoff is that the sensor has a response time of approximately one temperature update per second, which is slightly slower than existing temperature sensors. However, this response time is sufficient for devices that operate in the human body, homes and other environments where temperature do not fluctuate rapidly, researchers said.   Moving forward, the team is working to improve the accuracy of the temperature sensor. The team is also optimizing the design so that it can be successfully integrated into commercial devices.     Ref. ADT7410TRZ-REEL DS18B20

Researchers at Tokyo Institute of Technology have devised a low-cost approach to developing all-solid-state batteries, improving prospects for scaling up the technology for widespread use in electric vehicles, communications and other industrial applications. Ever since batteries were invented over 200 years ago, there has been a drive to improve quality and performance at reduced costs.Compared to common lithium-ion batteries that contain lithium ion conducting liquids, all-solid-state batteries of the future promise a suite of advantages: improved safety and reliability, higher energy storage and longer life cycles. The discovery of ‘superionic’ conductors — solid crystals that enable fast movement of ions — is spurring the development of such dream batteries, but promising designs have so far relied on the use of rare metals such as germanium, making them too expensive for large-scale applications. Ryoji Kanno and colleagues at Tokyo Institute of Technology (Tokyo Tech) have now discovered a new material with a low-cost, scalable approach that involves substituting germanium for two more readily available elements: tin and silicon. The new material achieved an ionic conductivity that exceeds that of liquid electrolytes. Reporting their findings in Chemistry of Materials, the team states: "This germanium-free lithium conductor could be a promising candidate as an electrolyte in all-solid-state batteries." Due to its high chemical stability and ease of fabrication, Kanno says that the new material widens the possibilities of fine-tuning solid electrolytes to meet diverse industry and consumer needs. In 2011, Kanno and his team, working in collaboration with Toyota Motor Corporation and Japan's High Energy Accelerator Research Organisation (KEK), published a landmark paper in Nature Materials that introduced a solid electrolyte with the structure Li10GeP2S12 (LGPS). This material became an important forerunner in the race to develop viable all-solid-state batteries. It exhibited an ionic conductivity of 1.2x10-2S cm-1 at room temperature, a level comparable with — and even exceeding some — liquid electrolytes used in existing batteries. The team went on to design other solid electrolytes based on the same LGPS crystal structure, with promising results. In their latest study, the researchers kept the same framework structure of LGPS, and finely adjusted the ratio and positioning of the tin, silicon and other constituent atoms. The resulting material LSSPS (composition: Li10.35[Sn0.27Si1.08]P1.65S12 (Li3.45[Sn0.09Si0.36]P0.55S4)) achieved an ionic conductivity of 1.1x10-2S cm-1 at room temperature, almost reaching that of the original LGPS structure. Although further work will be required to optimise performance for different usage purposes, the new material raises hopes for low-cost production without sacrificing performance. Kanno envisions that in addition to meeting current battery needs across all sectors, all-solid-state batteries will expand the possibilities of responding to new user needs arising from the IoT and the shift towards smart systems, as well as powering robots, drones and space and aircraft technologies among others in future.  Ref.KY605-NH12VPKY605-NH15VP

Scientists have spent decades searching for a safe alternative to the flammable liquid electrolytes used in lithium-ion batteries.Now Stanford University researchers have identified nearly two-dozen solid electrolytes that could someday replace the volatile liquids used in smartphones, laptops and other electronic devices. The results, based on techniques adapted from artificial intelligence (AI) and machine learning, are published in the journal Energy & Environmental Science."Electrolytes shuttle lithium ions back and forth between the battery's positive and negative electrodes," said study lead author Austin Sendek, a doctoral candidate in applied physics and first author on the paper. "Liquid electrolytes are cheap and conduct ions really well, but they can catch fire if the battery overheats or is short-circuited by puncturing."Battery fires led to the recent recall of nearly 2 million Samsung Galaxy Note7 smartphones, the latest in a series of highly publicized lithium-ion battery failures."The main advantage of solid electrolytes is stability," Sendek said. "Solids are far less likely to blow up or vaporize than organic solvents. They're also much more rigid and would make the battery structurally stronger."Searching for solidsDespite years of laboratory trial and error, researchers have yet to find an inexpensive solid material that performs as well as liquid electrolytes at room temperature.Instead of randomly testing individual compounds, the team turned to AI and machine learning to build predictive models from experimental data. They trained a computer algorithm to learn how to identify good and bad compounds based on existing data, much like a facial-recognition algorithm learns to identify faces after seeing several examples."The number of known lithium-containing compounds is in the tens of thousands, the vast majority of which are untested," Sendek said. "Some of them may be excellent conductors. We developed a computational model that learns from the limited data we already have, and then allows us to screen potential candidates from a massive database of materials about a million times faster than current screening methods."To build the model, Sendek spent more than two years gathering all known scientific data about solid compounds containing lithium."Austin collected all of humanity's wisdom about these materials, and many of the measurements and experimental data going back decades," said Evan Reed, an assistant professor of materials science and engineering and a senior author on the paper. "He used that knowledge to create a model that can predict whether a material will be a good electrolyte. This approach enables screening of the full spectrum of candidate materials to identify the most promising materials for further study."Screening criteriaThe model used several criteria to screen promising materials, including stability, cost, abundance and their ability to conduct lithium ions and re-route electrons through the battery's circuit.Candidates were selected from The Materials Project, a database that allows scientists to explore the physical and chemical properties of thousands of materials."We screened more than 12,000 lithium-containing compounds and ended up with 21 promising solid electrolytes," Sendek said. "It only took a few minutes to do the screening. The vast majority of my time was actually spent gathering and curating all the data, and developing metrics to define the confidence of model predictions."The researchers eventually plan to test the 21 materials in the laboratory to determine which are best suited for real-world conditions."Our approach has the potential to address many kinds of materials problems and increase the effectiveness of research investments in these areas," Reed said. "As the amount of data in the world increases and as computers improve, our ability to innovate is going to increase exponentially. Whether it's batteries, fuel cells or anything else, it's a really exciting time to be in this field."Reference:1215F101215F2X31215F6 

Instead of ordering batteries by the pack, we might get them by the ream in the future. Researchers at Binghamton University, State University of New York have created a bacteria-powered battery on a single sheet of paper that can power disposable electronics. The manufacturing technique reduces fabrication time and cost, and the design could revolutionize the use of bio-batteries as a power source in remote, dangerous and resource-limited areas."Papertronics have recently emerged as a simple and low-cost way to power disposable point-of-care diagnostic sensors," said Assistant Professor Seokheun "Sean" Choi, who is in the Electrical and Computer Engineering Department within the Thomas J. Watson School of Engineering and Applied Science. He is also the director of the Bioelectronics and Microsystems Lab at Binghamton."Stand-alone and self-sustained, paper-based, point-of-care devices are essential to providing effective and life-saving treatments in resource-limited settings," said Choi.On one half of a piece of chromatography paper, Choi and PhD candidate Yang Gao, who is a co-author of the paper, placed a ribbon of silver nitrate underneath a thin layer of wax to create a cathode. The pair then made a reservoir out of a conductive polymer on the other half of the paper, which acted as the anode. Once properly folded and a few drops of bacteria-filled liquid are added, the microbes' cellular respiration powers the battery. "The device requires layers to include components, such as the anode, cathode and PEM (proton exchange membrane)," said Choi. "[The final battery] demands manual assembly, and there are potential issues such as misalignment of paper layers and vertical discontinuity between layers, which ultimately decrease power generation."Different folding and stacking methods can significantly improve power and current outputs. Scientists were able to generate 31.51 microwatts at 125.53 microamps with six batteries in three parallel series and 44.85 microwatts at 105.89 microamps in a 6x6 configuration.It would take millions of paper batteries to power a common 40-watt light bulb, but on the battlefield or in a disaster situation, usability and portability is paramount. Plus, there is enough power to run biosensors that monitor glucose levels in diabetes patients, detect pathogens in a body or perform other life-saving functions. "Among many flexible and integrative paper-based batteries with a large upside, paper-based microbial fuel cell technology is arguably the most underdeveloped," said Choi. "We are excited about this because microorganisms can harvest electrical power from any type of biodegradable source, like wastewater, that is readily available. I believe this type of paper biobattery can be a future power source for papertronics."The innovation is the latest step in paper battery development by Choi. His team developed its first paper prototype in 2015, which was a foldable battery that looked much like a matchbook. Earlier this year they unveiled a design that was inspired by a ninja throwing star.Reference:AFPG804TL-5276/WAFPX-BATT