Basically, if your motorcycle won't charge or shuts off, one of the aforementioned parts has failed!A motorbike charging system component may fail in a variety of ways, all of which are very common: • The rectifier/regulator overheats and fails. The Reg/rec has a...
In order to power Sony’s handheld video recorder, the company initially marketed lithium-ion batteries in 1991. The International Space Station, electric vehicles, smartphones, and everything else you see today are all powered by batteries, making improved battery safety even more important.
Tesla became the first automaker to commercialize a battery-powered electric vehicle when it launched the Roadster in 2008. The market for lithium-ion (Li-ion) batteries is anticipated to reach USD 100.4 billion by 2025, with the automotive sector accounting for more than half of that amount.
Why is lithium-ion such a hot commodity?
The popularity of lithium-ion batteries is a result of the amount of power they can produce for their size and weight. Unlike lead acid batteries or NiMH battery packs, which have an energy density of 100 watt-hours per kilogram, a typical lithium-ion battery has an energy density of 150 watt-hours per kilogram (25 watt-hours per kg). Lead-acid batteries require 6 kilograms to hold the same amount of energy that a 1-kilogram lithium-ion battery can.
However, lithium-ion batteries are inherently flammable and particularly sensitive to high temperatures. Due to heat, these battery packs typically deteriorate much more quickly than they would otherwise. A lithium-ion battery pack that malfunctions will catch fire and can cause extensive damage. This necessitates taking fast action and developing battery safety regulations.
Several fires started by lithium-ion batteries have occurred recently. The COSCO Pacific, a ship in the Arabian Sea, caught fire on January 8, 2019, as a result of the spontaneous combustion of a lithium-ion battery. Four firefighters were hurt in April of last year when a 2MW battery at an APS facility in Arizona burst.
Rechargeable lithium batteries have the potential to start “fires that are difficult to extinguish and the batteries release fire that swiftly spreads,” according to Hans-Otto Schjerven, chief of the Vestfold Flames Department. These incidences are expected to rise as the use of electric vehicles spreads.
Let’s first examine how lithium-ion batteries function before discussing why they catch fire.
A lithium-ion battery pack is made up of modules of lithium-ion cells stacked on top of one another, temperature sensors, a voltage tap, and a battery management system (BMS) that controls the individual cells. The lithium-ion cell is similar to other cells in that it has an electrolyte between the cathode, which is a positive electrode, and the anode, which is a negative electrode. While the cathode is typically formed of diverse lithium minerals, such as lithium cobalt oxide (LCO), lithium nickel manganese cobalt (or NMC), etc., the anode is typically made of graphite (carbon).
Lithium ions flow through the electrolyte from the cathode to the anode when the cell receives a charging current. Although they travel a longer route outside the circuit, electrons still move. When a cell is discharged, the reverse movement occurs, and the electrons that result power the linked application.
The cell has been fully discharged and has to be charged once all of the ions have returned to the cathode.
Battery safety features like: have been incorporated into the design of lithium-ion cells
A. Vents with pressure sensors
Because batteries are pressured, they require a metal outside wall with a pressure-sensitive vent hole. This vent will let out additional pressure and stop other cells from catching fire if the battery is at risk of overheating and exploding from over-pressure (pressure buildup at 3,000 kPa).
B. The separater functions as a fuse
The majority of lithium-ion cells use a polyolefin separator, which has outstanding chemical stability, excellent mechanical qualities, and is reasonably priced. As soon like the cell heats up, it acts as a fuse. The separator melts under extreme heat when the core hits 130°C (266°F), which halts the movement of ions. The cell is immediately turned off by this action.
Without this protection, there would have been a risk that the failing cell’s heat would have reached the thermal runaway threshold and ignited.
C. Thermometer Readings That Are Positive (PTC)
This switch guards the battery from current spikes to stop it from overheating.
Like other chemistries, lithium-ion cells discharge themselves. Self-discharge is the loss of a battery’s stored charge without the electrodes or an external circuit being connected. Chemical processes inside the cell cause this to happen. Cell self-discharge rises with age, cycling, and high temperatures.
Temperatures may increase as a result of elevated self-discharge, which if unchecked could result in a Thermal Runaway, often known as “venting with flame.” Because there is minimal heat produced and very little energy discharged, a light short won’t result in thermal runway.
However, if the cell is damaged in some way and impurities get inside, there might be a serious electrical short and a significant current could flow between the positive and negative plates. When the temperature suddenly rises, the battery’s energy is released in a matter of milliseconds. Numerous thousands of cells are compressed together to form battery packs.
The heat produced by a failing cell during a thermal runaway might transfer to the following cell, making it also thermally unstable. The entire pack could be destroyed in a matter of seconds due to this chain reaction.