A new prototype of a lithium-sulphur battery – which could have five times the energy density of a typical lithium-ion battery – overcomes one of the key hurdles preventing their commercial development by mimicking the structure of the cells which allow us to absorb nutrients. @ cam.ac.uk
This gets us a long way through the bottleneck which is preventing the development of better batteries.
Next-generation smartphone battery inspired by the gut – [Link]
Steve Taranovich discuss about various ways to enhance Li-Ion batteries safety.
Typically, Lithium-ion batteries are safe and reliable. Just think about the $28B market they had in 2013 with a relatively small amount of fires and explosions. But every fire and explosion incident has the potential to cause a loss of life or serious personal injury (Not to mention the collateral material damage and cost).
Lithium-ion battery fires: 7 solutions for improved safety – [Link]
A new type of batteries called “Printable Solid-State (PRISS) Lithium-Ion Batteries” was designed by a group of researchers from the Ulsan National Institute of Science and Technology (UNIST, South Korea). The new battery is created from consecutive layers of printed composite materials.
With a simple stencil printing process followed by ultraviolet cross-linking, a solid-state composite electrolyte (SCE) layer and SCE matrix-embedded electrodes are consecutively printed on arbitrary objects of complex geometries, eventually leading to fully integrated PRISS batteries. Then the rheological properties of SCE paste and electrode slurry adjusted to get thixotropic fluid characteristics, along with well-designed core elements.
This technology yields many positive features, it eliminates the need for conventional microporous separator membranes and the extra processing steps of solvent drying and liquid-electrolyte injection.
With this new type of batteries, unlimited forms and sizes of batteries will be available for our various projects.
David Jones has another useful video tutorial about how to safely charge Lithium Ion and Lithium Polymer batteries with a bench power supply. The purpose of this tutorial is to learn how to use your lab power supply to charge your Lithium Ion battery when you don’t have a special charger circuit to do so.
He used NCR18650B in his tutorial, a 3.6V 3400mAh Lithium Ion battery from Panasonic.
David warned us that charging this type of battery is quite dangerous if we didn’t do it in the correct way. Even with the presence of protection circuit in Lithium Ion battery.
You can find the charging diagram in NCR18650B battery datasheet.
According to the datasheet, the charging current is 1625mA and the charging voltage is 4.2V. Charging consists of two stages, first one is the constant current stage where you must supply a 1625mA constant current and when the battery voltage reaches 4.20V, the second stage starts, which is the constant voltage stage. In this stage, the current will naturally drop down, and the cutoff is typically about 10% of charging current so it’s about 170mA.
This tutorial applies to all Lithium Ion and Lithium Polymer batteries not only NCR18650B.
You can perform this 2-stage charging using your power supply, but it must supports CC(Constant Current) and CV(Constant Voltage) modes. You can read the following Q&A in electronics.stackexchange to learn what constant current and voltage modes mean. You can build a power supply with CC and CV modes for yourself if you don’t have a budget to buy a ready made one.
David said that using this type of float charging/trickle charging is not recommended, because it will build-up or plate the metallic parts inside the battery. So It’s better to use dedicated ICs designed for the float charging.
LTC4013 is a highly integrated, high voltage multi-chemistry synchronous step-down battery charger controller. With a wide input voltage range that spans up to 60V, the LTC4013 uses temperature-compensated 3- and 4-stage charge algorithms to efficiently charge 12V and 24V lead-acid batteries. By Graham Prophet @ edn-europe.com
Alternatively, the LTC4013 will charge a multicell Lithium-based battery stack with float voltages near to the input supply. Mode pins define the float voltage and charge algorithm. Charge current is precision regulated to ±5% and programmable with a single resistor up to 20A (depending on the selection of external components). The LTC4013 features user-adjustable maximum power point tracking (MPPT) circuitry that enables simple power optimization in the case of power-limited sources such as solar panels. The MPPT open-circuit method corrects for panel temperature changes without the inconvenience of adding a solar panel temperature sensor. Applications include portable medical instruments, monitoring equipment, battery backup systems, industrial handhelds, industrial lighting, military equipment, ruggedized notebooks/tablet computers, plus remote powered communication and telemetry systems.
60V-input battery charger; Pb-acid & Li-ion charge algorithms up to 20A – [Link]
Numerous laboratories are working towards reducing or eliminating the accidental risks of Li ion batteries by working on solid electrolytes. Researchers at ETH at Zurich are developing unique solid materials which even when brought to high temperatures will not ignite. by Denis Meyer @ elektormagazine.com:
This represents a double advancement over current Li ion batteries which contain inflammable gel electrolytes, because not only does the fire risk disappear, but constraints over form-factor are also much less.
Lithium ion batteries that work best at 95°C – [Link]
SunDuino is a Single Board Computer with integrated Battery Charger, Voltage Regulators, I2C, Digital and Analog IO. It’s main benefit is that it can run a compiled C app for years on a small battery or forever using built in solar charger. A background RTOS provides SLEEP functions for reducing operating current to 100ua while providing 125ms periodic wakeups. Sunduino comes in 25W and 10W versions to better suit your application. Take a look at the manual and Datashseet. Also the schematic and PCB layout is available for free.
Key benefits of SunDuino:
Battery charging logic is optimized for long battery life using temperature monitor. The SunDuino is a software defined charger, it supports many battery chemistries and sizes.
Low current operation provides long battery life and runtime. An internal RTOS keeps battery monitoring, power event monitoring, user C Application and SLEEP mode all operating on a 100ua drain. Small batteries can run for years.
Regulated output voltages of +5. +3.3 and +/-12 for the powering of external hardware. Radios, other processors, relays and LEDs are examples of external hardware which requires regulated voltages.
Runs compiled C Applications and various library function for complete user control of power operation. Greatly simplifies system integration.
SunDuino – Run your C application using solar power – [Link]
A situation many can relate to: an empty smartphone battery and no outlet around! That’s exactly why I recycled an old laptop battery into an USB power bank.
This article will show you the basic powerbank circuit consisting of Lithium cell charging circuit, boost converter and toggle switch as well as my improved version with self activating boost converter and LED status indicator and homemade housing.
KA7OEI designed a circuit that disconnects the battery when it over-discharges. He writes:
The avoidance of overcharging is usually pretty easy to avoid: Just use the appropriate charging system – but overdischarge is a bit more difficult, particularly if the battery packs in question don’t have a “protection board” with them.
Lead acid batteries (almost) never come with any sort of over-discharge protection – one must usually rely on the ability of the device being powered to turn itself off at too-low a voltage and hope that that threshold is sensible for the longevity of a 12 volt battery system.
Disconnect circuit for 12 volt lead acid and lithium batteries – [Link]
Murata’s UMAL is a low-profile high capacity energy device. Designed to meet the demand for a slim high capacity energy source with a maintenance-free extended life cycle in wireless sensor nodes, the UMAL has charge/discharge and life-cycle characteristics superior to conventional secondary batteries. By Graham Prophet
The UMAL has a nominal voltage of 2.3 VDC, can supply 12 mAh with a maximum discharge current of 120 mA and is able to withstand load fluctuations. It has a low internal resistance of 200 mOhm and can operate over the temperature range of – 20C to + 70C.
Not a battery or a supercap, but a ‘thin laminate energy device’ – [Link]