Lithium Batteries are the most ideal type for electric vehicles. State of the art design and tested reliability has proven that having one of these powering your bike will provide you nothing short of a smile while saying “sweeeeeeet”.
Exceptional power output and cycle life also make these the most efficient. Here we will zone in on the main types of lithium batteries used in electric bikes and some history behind them.
Advancement & Improvement
In the 1970s these batteries were made commercially available. They were not rechargable at this point, attempts made in the 1980s resulted in explosive results because lithium as anode material was too unstable causing electrical shorts. It would heat up to melting temperature, then lead to thermal runaway / venting flames out fo the battery to put it in english. Leading now to the lithium – ion battery.
A stable, graphite anode type that had lower specific energy capability but ultimately safer than it’s predessecor. This is a low mainatance battery, a title not many other types can claim. No liquids, need for constant monitoring of discharge, and high energy output makes an excellent addition to an electric bike or motorcycle.
After much experimentation, trial and error. Lithium batteries are a common sight on electric bikes and e motorcycles. They are much lighter and more efficient than lead acid batteries are. Not to mention there is a huge difference in the amount of toxic materials used to produce it.
It is clear that we are utilizing greener technology into our lives in all ways. Computers, mobile phones, laptops and gaming consoles that can use a battery are the primary users of lithium batteries.
The superior performance comapred to a lead acid battery is thanks to it’s high energy density / voltage of 3.60V. Self discharge is minimal and does not require full cycling like lead acid or nickel. Lithium-ion uses a cathode (positive electrode), an anode (negative electrode) and electrolyte as the conductor.
In an electric bike, the positive lithium-ions travel across an electrolyte and a separator from an anode towards a cathode, which are two dissimilar conducting materials. The cathode then becomes more positively electrically charged than the anode. This creates a voltage between the anode and the cathode, which is essentially a driving force that pushes electrons between two points.
Types of Lithium Batteries
There are 3 main types of lithium batteries used in electric bikes and motorcycles. Lithium-Polymer (Li-po), Lithium-Cobalt-Oxide (LiCo02) and Lithium-Maganese-Oxide (LiMhn2o4). They vary slightly in performance but are suitable for low power applications like powering an e bike. Below we will break down each type and gain familiarity with each system.
The most popular battery for electric bikes. Highly maluble,contain no liquid, so these don’t require the protective cases that other batteries need. This absence of liquid means that it is more stable and less vulnerable to problems caused by overcharge, damage or abuse. Regardless of manufacture, you will be paying more money for better performance over a lead acid or Ni-cad battery.
High specific energy makes Lithium-cobalt the best choice for mobile phones, laptops and digital cameras. The battery consists of a cobalt-oxide cathode and a graphite-carbon anode. The cathode has a layered structure and during discharge, lithium ions move from the anode to the cathode. The flow reverses on charge. The drawback of a Lithium-cobalt is relatively short life span, low thermal stability, and limited load capabilities.So this type is okat for electric bikes, but better for smaller devices.
Just like any other lithium battery, but uses Lithium-Maganese as cathode material. The design makes a three dimensional spinel that improves the ion flow on the electrode. Low resistance from the cells enables fast charging and discharging.
It can provide about one third of the power output of a lithium-cobalt battery, but is a flexible design that can be aimed towards either better longevity, maximum current load or higher capacity.
Lithium-Maganese can be mized with other metals to create these different scenarios. One for exapmle is Lithium-Nickel-Maganese-Cobalt-Oxide. The cathode is usually a combination of one thrid nickel, one thrid maganese, and one thrid cobalt. This is a great blend that reduces the costs of production thanks to using less cobalt.
One other good combo is NCM, which is 5 parts nickel, 3 parts cobalt, and 2 parts maganese.These types ore being preferred by manufactures and are one of the most popular type of lithium battery used by e bikes.
Here are the advantages and disadvantages of Lithium batteries.
- High specific energy and load capabilities.
- Long cycle and shelf life, basically maintanaince free.
- High capacity and low resistance.
- Low self discharge
- Requires protection circuts to prevent thermal runaway.
- Degrades at higher tempertures when fully charged.
- Cannot rapid charge at freezing temperature.
- Requires shipping permits of carrying a large quantity of batteries.
Greener, Faster, Stronger!
Contents of the Lithium battery contain much more recycleable materal than the old lead acid battery. All batteries should be disposed & recycled properly, using ones that are not harmful to the environment reduce the impact of breakdown costs to reuse these materials.
As improvements continue to be made to existing designs, we are moving together towards a brighter and more fit future together with electric bikes.
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