Tag Archives: Battery

Could Sodium-ion Batteries be a Replacement for Li-ion Batteries?

Batteries made by Tiamat, a sodium battery startup spun off from the National Center for Scientific Research in France.

In early 1990s lithium-ion batteries started gaining popularity as a substitute for nickel-cadmium batteries. They have higher energy density, low self- discharge, and low maintenance, but it was soon found that they have short life span, unstability which causes security concerns and creates the need for protection circuits (to maintain it within safe limits), and are really expensive to produce. Lithium is scarce (or is soon going to be), only 0,06% of earth crust is made of this material and its mainly found in South America. A start up called Tiamat formed by scientists at several French universities proposed an alternative to lithium-ion batteries, they developed the first sodium-ion battery in industry standard 18650 cell size.

Unlike Lithium, sodium makes up 2.6% of earths crust which makes it the sixth most abundant element. As a raw material sodium sells at about $150 a ton compared to $15,000 a ton for lithium. Sodium batteries are cheaper to produce than lithium batteries, leading to a lower selling price. Also, the lifespan is about ten years compared to lithium which is 4 years and Sodium-ion batteries can last for up to 5000 charge/discharge cycles. Tiamat batteries are not a fire hazard, and provide more stability for a cheaper price.

Scientists want to use these batteries mainly for mass storage of interment renewable energies such as solar o wind. Tiamat is not looking to make Li-ion batteries disappear, instead they want to focus on their long lasting power, and use it for stationary storage. This type of battery could be used in electric cars to allow lasting trips with short recharge time. Production has not started, but when it is approved, and they start to sell France could become a leader in this type of technology. This startup has the support of RS2E (Réseau sur le stockage électrochimique de l’ énergie) a French research network dedicated to energy storage devices, and they plan to launch the product on 2020.

Nowadays, lithium batteries are used mainly for smartphones, laptops, and cars that means that if a new technology was going to replace them, a much better alternative would be needed. Even when sodium batteries are cheaper and safer they still have performance issues that could affect their sales, but as Tiamat said they are not looking to replace these and their market is completely different. For now, the cells produced offer only about half of the energy density of Li-ion and are yet to be improved in many aspects.


Improving Wearables with Flexible and Rechargable Battery

The stretchable batteries were printed on fabric for this demonstration. They make up the word NANO on the shirt and are powering a green LED that is lit in this picture. (Image courtesy of Jacobs School of Engineering/UC San Diego.)

Nowadays, there is a lot of technology that implements wearables in fashion, medicine, worker safety, accessories and much more. Many wearables are coupled with uncomfortable charging cables that are irritating for users to handle, some even have big batteries that make wearables a burden instead of an advantage. Statistics show that people tend to abandon this devices after only 6 months of buying them, and battery life and portability is one of the issues. Addressing portability, the nanoengineers at the university of California San Diego have developed a new material that allows the creation of flexible, stretchable, and rechargeable batteries which can be printed into clothes.

This material named SIS can be expanded twice its size in any direction without any damage. SIS is made from a hyper elastic polymer material made from isoprene and polystyrene. The ink used to print the batteries is made with Zinc silver oxide with bismuth (to make it rechargeable). The whole flexible battery is made from both SIS and the ink.  When zinc battery runs out, their electrodes react with the liquid electrolyte inside the battery which eventually shorts circuits the battery, bismuth prevents this from happening and ensures battery durability.

The prototype has 1/5 the capacity of a hearing aid rechargeable battery and it´s 1/10 as thick. It costs only $0.5 USD to produce and uses commercially available materials which makes it cheaper and smaller, but not as efficient as a common wearable battery. Two of these batteries are needed to power a 3 v LED, so a lot of them would be needed to power a bigger device.

The engineers are working towards improving performance to make them a good choice for wearable developers. They also want to extend their work towards lithium ion batteries, supercapacitor, and photovoltaic cells. Commercially, the short-term objective is to replace coin batteries for printable batteries which have a competitive price.

When performance is improved these batteries could power all kind of wearables for medical purposes such as shirts that can detects fever, or glucose sensor in diabetic patients. Also, for recreational purposes such as a sweatshirt with LEDs to run during night, or a shirts that detects movement and helps you with your movements while playing golf. Engineers for this project should consider implementing wireless charging to make it even more comfortable for the user by ending the need of cables and small connectors which are a nightmare for most of the people.


Solid-state battery – a hybrid of battery and capacitor

With CeraCharge, TDK has developed the world’s first solid-state battery in SMD technology. In contrast to most common battery technologies, CeraCharge works without any liquid electrolytes. by Christoph Hammerschmidt @ eenewseurope.com:

Similar to ceramic capacitors, the CeraCharge is based on multilayer technology and combines a high energy density in the smallest possible space with process reliability in the manufacture of multilayer components. The use of a ceramic solid as electrolyte also excludes the risk of fire, explosion or leakage of electrolyte fluid.

In the compact size EIA 1812, the battery, which can be rechargeable several dozen to 1000 times, offers a capacity of 100 µAh at a nominal voltage of 1.4 V depending on the requirements. In the short term, currents in the range of a few mA can also be drawn.

Wireless power in AA battery format

Ossia has created the world’s first wirelessly-powered alternative to disposable AA batteries. The “Forever Battery” puts a long distance wireless power receiver into an AA battery format. The technology can receive up to 4W from a nearby RF transmitter (Cota transmitter), and includes a data link. [via]

Forever Battery bridges the gap between the battery-wire age and the wireless power era,” said Mario Obeidat, CEO of Ossia. “When people see how Cota Real Wireless Power can be implemented in a AA battery, they will start to see the vision of Cota everywhere. The Forever Battery will create awareness of Cota and provide confidence that devices will be powered when it matters.

2 X AA Battery To 6V Boost Converter For Arduino Nano

This project is simple solution to power Arduino Nano from two 1.5V batteries. Circuit converts 2 X AA alkaline battery power into 6V 100mA using boost topology. Circuit uses SOT223-6 pin TLV61046A boost converter IC. The TLV61046A is a highly integrated boost converter designed for applications such as PMOLED panel, LCD bias supply and sensor module. The TLV61046A integrates a 30-V power switch, an input to output isolation switch, and a rectifier diode. It can output up to 28 V from input of a Li+ battery or two alkaline batteries in series. The TLV61046A operates with a switching frequency at 1.0 MHz. This allows the use of small external components. The TLV61046A has typical 980-mA switch current limit. It has 7-ms built-in soft start time to reduce the inrush current. The TLV61046A also implements output short circuit protection, output over-voltage protection and thermal shutdown. R1 and R2 connected to FB pin to set the output voltage 6V. R1 and R2 can be altered to set higher output voltage, refer data sheet for calculation. The board can be used as Arduino Nano shield or as stand-alone boost converter. It directly fits on top of the Arduino Nano and output is connected to VIN and GND pins of Nano.

2 X AA Battery To 6V Boost Converter For Arduino Nano – [Link]

Researchers Developed Low Cost Battery From Graphite Waste

Lithium-ion batteries are flammable and the price of the raw material is increasing. Scientists and engineers have been trying to find out a safe yet efficient alternative to the Lithium-ion technology. The researchers of Empa and ETH Zürich have discovered promising approaches as to how we might produce powerful batteries out of waste graphite and scrap metal.

Kostiantyn Kravchyk and Maksym Kovalenko, the two chief researchers of the Empa’s Laboratory for Thin Films and Photovoltaics, led the research group. Their ambitious goal is to make a battery out of the most common elements in the Earth’s crust – such as graphite or aluminum. These metals offer a high degree of safety, even if the anode is made of pure metal. This also enables the assembly of the batteries in a very simple and inexpensive way.

In typical lithium-ion battery design, the negative electrode or anode is made from graphite. This new design, however, uses graphite as the positive electrode or cathode. In order to make such batteries run, the liquid electrolyte needs to consist of special ions that form a kind of melt and do not crystallize at room temperature. The metal ions move back and forth between the cathode and the anode in this “cold melt”, encased in a thick covering of chloride ions.

Alternatively, large but lightweight and metal-free organic anions could be used. But, this raises some questions which cannot be solved easily – where are these “large” ions supposed to go when the battery is charged? What could be a suited cathode material? In comparison, the cathode of the lithium-ion battery is made of a metal oxide which can easily absorb the small lithium cations during charging. This does not work for such large organic ions.

To solve the problem, Kovalenko’s team came up with a unique and tricky solution: the researchers turned the principle of the lithium-ion battery upside down. In Kovalenko’s battery, the graphite is used as a cathode; i.e., the positive pole. The thick anions are deposited in the intermediate spaces in the graphite. While searching for the “right” graphite, they found that waste graphite produced in steel production (known as kish graphite) works the best as a cathode material. Natural graphite is suitable when it is in the form of coarse flakes and not too finely ground.

uBoost Single AA to 3.3v 100mA Power Supply

µBoost is a Single AA powered, 3.3v 100mA power source and flashlight and it can run low power devices.

µBoost is small, portable, 3.3v 100mA power source for low power devices like Arduino Mini. It has white power LED and can usable as flashlight. Also it has “Battery OK” indicator that asserts when the battery voltage drops below 0.9v.

There is a 3mm hole on top, so you can hang it easily. You can simply turn it on/off by pressing the power button. It works as flip-flop.

uBoost Single AA to 3.3v 100mA Power Supply – [Link]

Rechargeable Magnesium Batteries – Safer And Cheaper Than Li-ion Batteries

Researchers at the University of Houston reported in the journal Nature Communications the discovery of a new design that significantly improves the development of a battery based on magnesium. Magnesium batteries are considered as safe resources of power supply – unlike traditional lithium-ion batteries. They are not flammable or subject to exploding – but their ability to store energy is very limited. But the latest discovery of the new design for the battery cathode drastically increases the storage capacity.

Energy diagrams for the intercalation and diffusion of Mg2+ and MgCl+
Energy diagrams for the intercalation and diffusion of Mg2+ and MgCl+ in magnesium batteries

In order to make magnesium batteries, the magnesium-chloride bond must be broken before inserting magnesium into the host, and this is very hard to do. Hyun Deog Yoo, the first author of the paper, said,

First of all, it is very difficult to break magnesium-chloride bonds. More than that, magnesium ions produced in that way move extremely slowly in the host. That altogether lowers the battery’s efficiency.

The new battery technology stores energy by inserting magnesium monochloride into titanium disulfide, which acts as a host. By keeping the magnesium-chloride bond intact, the cathode showed much faster diffusion than traditional magnesium batteries.

The researchers managed to achieve a storage capacity density of 400 mAh/g – a quadruple increase compared with 100 mAh/g for earlier magnesium batteries. This achievement even overpowered the 200 mAh/g cathode capacity of commercially available lithium-ion batteries. Yoo, who is also the head investigator with the Texas Center for Superconductivity at UH, confirmed this fact.

The cell voltage of a magnesium cell is only 1V which is significantly less than a lithium-ion battery which has 3.7V cell voltage. Higher cell voltage and high cathode capacity made Li-ion batteries the standard. Li-ion batteries suffer from an internal structural breach, known as dendrite growth what makes them catch fire. Being an earth-abundant material, magnesium is less expensive than lithium and is not prone to dendrite growth.

The magnesium monochloride molecules are too large to be inserted into the titanium disulfide using conventional methods. The trick they developed is to expand the titanium disulfide to allow magnesium chloride to be inserted rather than breaking the magnesium-chloride bonds and inserting the magnesium alone. Retaining the magnesium-chloride bond doubled the charge the cathode could store. Yoo said,

We hope this is a general strategy. Inserting various polyatomic ions in higher voltage hosts, we eventually aim to create higher-energy batteries at a lower price, especially for electric vehicles.

DIY Arduino Battery Capacity Tester

deba168 @ instructables.com writes:

I have salvaged so many old lap-top batteries ( 18650 ) to reuse them in my solar projects.It is very difficult to identify the good cells in battery pack.Earlier in one of my Power Bank Instructable I have told, how to identify good cells by measuring their voltages, but this method is not at all reliable.So I really wanted a way to measure each cell exact capacity instead of their voltages.

DIY Arduino Battery Capacity Tester – [Link]

Integrated 36V buck battery charger provides seamless backup power

By Graham Prophet @ eedesignnewseurope.com:

LTC4091 is a complete lithium-ion battery backup management system for 3.45V to 4.45V supply rails that must be kept active during a long duration main power failure. The LTC4091 employs a 36V monolithic buck converter with adaptive output control to provide power to a system load and enable high efficiency battery charging from the buck output.

Integrated 36V buck battery charger provides seamless backup power – [Link]