Tag Archives: Battery

Nanotechnoloy – Nano coating prevents exploding Li-ion batteries

Lithium-ion batteries are very popular as they’re lightweight and have high energy density. But at the same time, li-ion batteries are very sensitive to overcharge/over discharge. An internal short circuit can cause fire and it may even lead to a violent explosion. Fortunately, nanotechnology found a way to prevent this kind of nightmare. How? let’s discuss:

Why Does li-ion Battery Explode?

When a device draws too much power from a Li-Ion battery, it heats up and thus melts the internal separator between the two flammable electrolytes. This phenomenon ignites a chemical reaction between the electrolytes causing them to explode. Once their package ruptures, the oxygen in the surrounding air helps the flammable electrolytes to catch fire. The fire then spreads quickly to other cells and loads a thermal runaway.

Thermal runaway in Li-ion Battery
Thermal runaway in Li-ion Battery

During a thermal runaway, the high heat of the damaged or malfunctioning cell can propagate to the next cell, causing it to become completely thermally unstable as well. In some worse cases, a chain reaction occurs in which each cell disintegrates at its own timetable.

So, in a nutshell, Li-ion cells possess the potential of a thermal runaway. The temperature quickly rises to the melting point of the metallic lithium and cause a violent reaction, which finally causes an explosion.

How Can Nanotechnology Prevent This?

Recently conducted research shows that atomic layer deposition (ALD) of titania (TiO2) and alumina (Al2O3) on Ni-rich FCG NMC and NCA active material particles could substantially improve Li-ion battery’s performance and allow for increased upper cutoff voltage (UCV) during charging, which delivers significantly increased specific energy utilization.

Atomic Layer Deposition in li-ion CellsAtomic Layer Deposition in li-ion Cells
Atomic Layer Deposition in li-ion Cells

 

A company called Forge Nano claims to prevent this thermal runaway situation by never letting it get started even if the battery electrodes are shorted out. Forge Nano’s precision coatings on cathode and anode powders protect against the most common degradation mechanisms found in Li-ion batteries.

The benefits of Forge Nano precision coatings include extended battery life and greater safety, especially in extreme situations such as high-temperature operation, fast cycling rates, and overvoltage conditions.

By implementing lithium-based ALD films in nanostructured 3D lithium-ion batteries, significant gains in power density, cycling performances during charge/discharge, and safety is noticed.

What’s the Result?

Some of Forge Nano’s accomplishments in the Li-ion battery space includes:

  • Increased lifetime of commercial cathode material by as much as 250%
  • 15% higher energy density in large format pouch cells (40 Ah) that pass nail penetration testing
  • 60% reduced gas generation in cathode material
  • A low-cost high-voltage cathode powder with exceptional performance
  • Increased rate capability of conventional materials for enhanced fast charge acceptance using Forge Nano’s proprietary solid electrolyte coatings

    ForgeNano Claims Their Technology as Best Solution
    ForgeNano Claims Their Technology as Best Solution

Since the solution found by the research, Forge Nano has been working on a commercial version of the product that they finally believe they can place in the market very soon.

Next-generation smartphone battery inspired by the gut

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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]

Lithium-ion battery fires: 7 solutions for improved safety


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]

Printable battery paves the way for custom-shape power sources

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.

Representation of the PRISS Battery production process
Representation of the PRISS Battery production process

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.

Source: Elektormagazine

Using A Bench Power Supply To Charge Lithium Ion Batteries

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.

NCR18650BBattery

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.

LiionProtec

You can find the charging diagram in NCR18650B battery datasheet.

NCR18650BChargingdiag

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.

LiIonBatteries

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’s Power Supply Setting With 4.2V CV and 1700mA CC
David’s Power Supply Setting With 4.2V CV and 1700mA CC
The Battery Charges in The First CC Stage Sinking 1698mA
The Battery Charges in The First CC Stage Sinking 1698mA

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.

David mentioned in his video that a complete tutorial is available for whom who want to know in details how to charge lithium ion battery.

 

60V-input battery charger; Pb-acid & Li-ion charge algorithms up to 20A

160901edne-linear4013
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]

Lithium ion batteries that work best at 95°C

20160822142526_li-ion-solide

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 – Run your C application using solar power

BB25E_350T

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:

  1. 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.
  2. 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.
  3. 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.
  4. 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]

RELATED POSTS

DIY USB power bank from laptop battery

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DIY USB power bank made from an old laptop battery @ DoItYourselfGadgets:

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.

DIY USB power bank from laptop battery – [Link]

Disconnect circuit for 12 volt lead acid and lithium batteries

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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]