Lithium-ion VS NiMH Batteries

What is the essential difference between lithium batteries and nickel-metal hydride batteries?

The most common applications as an example:

Lithium batteries are more suitable for cell phones.

In digital cameras, the instantaneous current is huge. Therefore, the power consumption is also much larger than the cell phone. We should use nickel-metal hydride batteries in digital cameras.

What is a Lithium-Ion battery?

A Li-ion battery is also a rechargeable battery. It has a cathode made of lithium metal oxide and an anode usually made of graphite. Compared to NiMH batteries, Li-ion batteries have a higher energy density. In addition, Li-ion batteries have a very long lifespan of between 300 and 500 charge cycles. Lithium-ion batteries are used in many products, including cars, laptops, cell phones, and so on.

What is a NiMH battery？

Similar to the chemical process of NiCd batteries, the positive electrode utilizes nickel hydroxide. Instead of cadmium, the negative electrode is made from a hydrogen-absorbing alloy. Compared to NiCd batteries, NiMH batteries can have two to three times greater capacity and higher energy density.

NiMH battery advantages and disadvantages

Advantages

• High Energy Density

NiMH batteries have a high energy density. Their average capacity is 2200mAh. It is more than the 1500mAh found in Li-ion batteries. When you get into NiMH vs. lithium batteries, this is the first difference you need to know.

• Good compatibility

You can power ten devices using a NiMH battery with one pack. NiMH batteries are standard-sized, so they can be used with any device using size AAA or AA. The sizes of NiMH are different from Li-ions. They depend on the model or manufacturer of the device.

• Good security

They are safer than lithium-ion batteries because they contain less active material. Li-ion batteries can explode if they are overcharged or short-circuited. This is the difference in safety between NiMH batteries and lithium-ion batteries.

• Fully Dischargeable

They can still be charged when the NiMH batteries reach 0 charges. However, they must not experience reverse polarity; otherwise, they may be damaged.

Disadvantages

• High Self Discharge Rate

NiMH batteries pay a significant portion of their monthly charge. This number is approximately 5% the first week following the charge and around 50% the first month. There are several low self-discharge rate types. These are less reliable than standard NiMH but have higher capacities.

• Not reliable for low-load devices

It is not recommended to use NiMH batteries in devices like clocks. They will lose charge quicker due to self-discharge than they do from the load. Instead, use alkaline, lithium, or Li-ion batteries.

• Low Voltage Output

Each AA Cell can only provide 1.2v, while Li-ion cells can deliver 3.7v.

• Long Charging time

A standard charge time for NiMH batteries is between 10-12 hours. These cells may be damaged if they are charged too fast. The charging time for Li-ion batteries is approximately 1-3 hours, depending on their capacity.

• Sensitive To Extreme Temperatures

The output of the NiMH batteries will drop at extreme temperatures. These temperatures can be tolerated by Li-ion batteries to a certain extent.

Li-ion battery advantages and disadvantages

Advantages

• Reliable

These batteries have a much lower self-discharge than NiMH batteries. They can also be used in low-current devices such as watches or clocks.

• Small

These batteries are lighter and smaller than NiMH. This is the difference in shape between lithium-ion vs. NiMH batteries.

• Higher Voltage Output

One cell can produce 3.7V, while two NiMH cells can only deliver 2.4V.

• Faster Charge

Li-ion batteries can be charged in 1-3 hours, depending on the capacity. This is faster than the 10–12 hours required for NiMH batteries. Regarding charging time, there is a vast difference between Li-ion and NiMH batteries.

• Temperature Tolerant

These cells can withstand lower temperatures and higher environments than NiMH cells.

• Higher Energy Density

Li-ion battery has a higher charge per gram than a NiMH battery.

Disadvantages

• Lower Capacity

These cells have an average capacity of 1500 mAh, compared to the average 2200 mAh of NiMH cells.

• Incompatible

Different battery pack manufacturers make different sizes for Li-ion battery packs, so they are only compatible with a certain set of devices. NiMHs come in standard sizes.

• Less safe

Ions can be very active. They are very reactive and can generate lots of heat. These cells have circuits. They can be used to monitor temperature and voltage. The circuits stop the cells from exploding.

• Not Fully Chargeable

A Li-ion battery that is fully discharged will cause it to be damaged. You can shock-charge it, but it will lose its efficiency. This type of battery should be charged at least 50%.

Ni-MH VS Li-Ion Battery, Which Is Better?

Li-ion batteries are better than NiMH on the performance scale in most categories. Li-ion batteries last five years, 2 or 3 times longer than NiMH batteries, which only last two to five years. The Li-ion battery also charges faster, can withstand extreme temperatures, and lasts longer than NiMH. NiMH batteries are more expensive than Li-ion and need little maintenance.