Differences Between NiMH and Li-ion Rechargeable Batteries

In the early 1990s, mostly portable devices were powered with nickel-cadmium (NiCad) batteries. Since NiCad batteries were low cost and had a simple sharing process, they were low power and came with toxic materials that had bad effects on the environment. So NiMH and Lithium-ion (Li-Ion) batteries are used as replacements for Ni-Cad batteries since has better features than the older ones that will covered here. So let’s get started with NiMH vs Lithium-ion (Li-Ion) batteries

Table of Contents

What does NiMH for battery

NiMH full form is Nickel metal hydride and a common type of rechargeable battery used for small devices, remote control, and other electronic devices. NiMh comes with inner negative electrodes that are created with hydrogen-absorbing alloys that differentiate from other nickel batteries. Based on capacity and enegy density, it is considered an effective nickel battery

What does li-ion for battery

A lithium-ion battery is a recharable battery that comes with the latest design and technology as compared to other batteries. It comes with lithium-ion alloy since it has an electrochemical component with carbon for a high enegy density rating and low weight. It is commonly used for household electronics, mobile devices tablets, power tools, etc, and also used for energy storage systems.

Differences between NiMH vs Lithium-ion (Li-Ion) batteries

Size and weight

NiMh battery is small in size and heavy weight as compared to Li-Ion battery. For two-way radio users, weight is the main factor thatn size.

Power output

NiMh battery provides 1.2 volts but lithium-ion batteries provide 3.6 volts per cell

Memory effect

NiMH batteries are also highly affected by the memory effect as compared to Li-Ion batteries which can affect battery capacity for having full charge with time.

What is the “memory effect” in a battery?

NiMh battery is affected severely by the memory effect. It means if there is if we frequently recharge the battery when it is partially discharged, the battery effectively memorizes reduced working life and loses the capacity for a full charge. The reduced usage time of the radio between charges can cause issues for devices where it is used.

Li-ion battery is affected hardly by the memory effect, so it is not for the battery to completely discharge, or recharge it at any time with a small effect on future charge capacity.

Do NiMH batteries suffer from memory effects?

NiMh battery is not affected by memory effect significantly. It makes them easy to maintain and does not certain care. With that NiMh battery is environmentally tale friendly since not come with heavy metals

Will NiMH Batteries Last as Long as a Lithium Battery?

If the NiMh battery is occasionally overcharged, small crystals of electrodes, affect their feature to complete charge, and as a result, the battery loses voltage. Undercharging can result in low service whereas overcharging can result in cycle life. The best method is to solve it with use of the best MBS that handles the charging process so battery overcharging and damage effects can be controlled. The low-end charger uses timers as compared to actively monitoring voltage for finding cut-off charge current. Normally moderate rate two to three hours smart charger is used for NiMh battery. high-speed charging can affect battery working life.

Pros and Cons of Li-ion vs Ni-mh Battery

Pros of li-ion:

It has a high capacity rating of about 2500mAh.
Its voltage rating is 3.2 volts and low weight battery and easy to use
It offers fast charging.
The low self-discharge rate of about 3.5 percent per month means the lithium-ion battery has features to store or be left idle for a longer duration without losing its initial charge.
its working life is about ten years for normal use conditions.
it has features to work for a larger temperature range of (-20-60℃).
These batteries do not need maintenance.
it supported different devices

Cons of li-ion:

It is high cost thatn Ni-Mh battery

Pros of ni-mh:

It is compatible with different devices since they are structured for battery sizes like AA and AAA.
It does not have active materials so easy to use.
It can fully discharge about zero percent without issue for the battery
It is lower cost than Li-ion batteries.

Cons of ni-mh:

Ni-Mh has a high self-discharge rate and can lose about 50 percent of the initial charge in one month. It is applicable for types of ni-mh batteries not for all.
It is a low voltage of about 1.2 volts and is less than lithium-ion batteries.
Ni-Mh comes with a low charge time of about 8 to 12 hours since fast charging can result in damage to the battery.
It is sensitive to temperature variation since voltage level losses for high-temperature

Is NiMH the same as lithium Ion

For Li-ion vs ni-mh, they are not the same and not interchanged. These batteries are rechargeable and power common range devices by li-ion provdies power to differnt devices than ni-mh batteries.

NiMh battery is low cost, li-ion is high enegy density and voltage and adaptable and environmentally friendly than ni-mh batteries.

What type of rechargeable battery lasts longer

The Li-ion battery lasts longer having a low self-discharge rate and working life, it can work about 4000 cycles which is ten years while Ni-MH works for three years

Is NiMH safer than lithium-ion

Ni-Mh battery is safe to use, but easily susceptible to variations in temperature that affect battery overcharging resulting the fire hazards. Li-Ion battery is a safe battery

Features of Li-ion vs Ni-mh battery

Features	Ni-MH	Li-ion
Cell Voltage (V)	1.2	3.6
Specific Energy	1 to 80 (Wh/kg)	3 to 100
Specific Power (W/kg)	<200	100 – 1000
Energy Density (kWh/m3)	70 – 100	80 – 200
Power Density (MW/m3)	1.5 – 4	0.4 – 2
Efficiency (%)	81	99

Components of a NiMH Battery Cell

Positive Electrode (Cathode):

The positive electrode of the NiMh battery is created with nickel hydroxide (Ni(OH)2) and the active material can be different. The main features of nickel hydroxide are high energy density and stability. This stability feature it best for charge/discharge cycles.

Negative Electrode (Anode):

The negative electrode of the NiMh battery is made with active material, like lanthanum, and transition metals, nickel.
The negative electrode is coated with a conductive material such as nickel. It helps to shift electrons back and forth between positive and negative electrodes.

Electrolyte:

The electrolyte in NiMh battery is medium for ion transport in the battery. It is alkaline of 20% to 40% weight alkaline hydroxide solution.
PH level and concentration of the alkaline solution is important for excellent battery performance.

Separator:

It is made with non-woven polyolefin. This porous membrane parted positive and negative electrodes avoids short circuits and helps ions to move back and forth

Components of a Lithium-Ion Battery Cell

Cathode:

The cathode in a lithium-ion battery is the positive electrode. It is where lithium is stored. The high amount of lithium, the high capacity of the battery. The cathode is coated with active materials for transferring lithium ions. Active materials are lithium oxide.

Anode:

The anode is the negative electrode and it is made with graphite. Like cathode, it is also coated with active material. If the battery is charging, lithium-ion is stored in anode

Electrolyte:

The electrolyte in lithium-ion battery helps lithium ion to move back and forth between the cathode and anode during the charging and discharging process. It is made with salts, solvents, and additives. Speed of lithium-ion based on electrolyte used.

Separator:

The separator keeps the cathode and anode parted and makes sure the battery is easy to use. it is a porous material that helps lithium to move. Some separators used in lithium-ion batteries such as polyethylene (PE) and polypropylene (PP).

Can charge a NiMH battery with a li-ion charger?

No, it is not referred to since both batteries come with different chemistries and are not supported by each other for the same charge.

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Faqs

Which is better NiMH or Li-ion rechargeable batteries?

Lithium-ion rechargeable battery comes with longer longevity thatn NiMh batteries, about 700 to 950 cycles thatn 500 to 800 charge cycles for NiMH batteries

Can I replace NiMH battery with Li-ion?

As there is a voltage difference so direct replacement of NiMh with Li-Ion for devices used for NiMh can casues problems until devices have features to handle high voltage. Since high voltae can affect the components

Which battery is better LiPo or NiMH?

The weight-to-power ratio for LiPo batteries is good. LiPo battery is less weight and can store the same amount relative to capacity as NiMH batteries.
The power output of LiPo batteries is higher for quality and quantity.

What are the disadvantages of NiMH batteries?

The main disadvantages of nickel metal hydride batteries is high cost, strong self-rate, and high heat for high temperatures. Hybrid electric cars, but rechargeable electrical vehicles use batteries due to difficulties offered by them.

Is NiMH cheaper than lithium?

NiMh battery comes with a lower enegy density thatn lithium-ion battery, and pack energy to power vehicles. This battery is easier to afford than lithium-ion batteries, and low cost when hybrid vehicles are mass-produced.

What voltage do I charge my NiMH battery?

Referred schematic for 3-cell NiMh battery pack. The charge source for applications must be constant current or current limited supply having open circuit voltage between 5V and 12V.

Can I charge a Li-ion battery with a regular charger?

We can use a normal SLA charger to charge lithium batteries. Power-Sonic recommends charging batteries with a charger best for chemistry. It is also suggested to check all lithium batteries for less voltage for about 3 to 4 months and charge if required

What is the lifespan of NiMH vs Li-ion batteries?

they have a working life of about five years, as compared to NiMh’s life cycle of 2 to 5 years. Li-Ion batteries fastly get charge best work for extreme conditions and has charged for a longer duration than NiMH batteries.