Title: Which battery works better - alkaline, lithium, nickel cadmium, or nickel metal hydride?
Subject: Electricity
Grade level: Middle School - Grades 7-9
Academic Level: Ordinary
Project Type: Experimental
Cost: Low
Awards: 2nd place, Canada Wide Virtual Science Fair (2006)
Affiliation: Canada Wide Virtual Science Fair (VSF)
Year: 2006
Description: AA batteries (alkaline, lithium, nickel cadmium and nickel metal hydride) were tested in five identical mini maglite flashlights, which run on two AAs each. The batteries went on for an hour and then off for an hour. This was repeated a few times then the batteries' milliamps were measured by an multimeter.
Link:http://www.virtualsciencefair.org/2006/glaz6j2/

Short Background

Alkaline Batteries

Alkaline batteries and Alkaline Cells (a battery being a collection of multiple cells) are a type of disposable battery or rechargeable battery dependent upon the reaction between zinc and manganese (IV) oxide (Zn/MnO2).

Compared with zinc-carbon batteries of the Leclanché or zinc chloride types, while all produce approximately 1.5 volts per cell, alkaline batteries have a higher energy density and longer shelf-life. Compared with silver-oxide batteries, which alkalines commonly compete against in button cells, they have lower energy density and shorter lifetimes but lower cost.

The alkaline battery gets its name because it has an alkaline electrolyte of potassium hydroxide, as opposed to the acidic electrolyte of the zinc-carbon batteries which are offered in the same nominal voltages and physical size.

Lithium Batteries

Lithium batteries are disposable (primary) batteries that have lithium metal or lithium compounds as an anode. Depending on the design and chemical compounds used, lithium cells can produce voltages from 1.5 V to about 3.7 V, twice the voltage of an ordinary zinc-carbon battery or alkaline cell. Lithium batteries are widely used in products such as portable consumer electronic devices.

Nickel-Cadmium Batteries

The nickel-cadmium battery (commonly abbreviated NiCd) is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes. There are two types of NiCd batteries: sealed and vented.

Nickel-Metal Hydride Batteries

A nickel-metal hydride battery, abbreviated NiMH, is a type of rechargeable battery similar to a nickel-cadmium (NiCd) battery. The NiMH battery uses a hydrogen-absorbing alloy for the negative electrode instead of cadmium. As in NiCd batteries, the positive electrode is nickel oxyhydroxide (NiOOH). A NiMH battery can have two to three times the capacity of an equivalent size NiCd. However, compared to the lithium-ion battery, the volumetric energy density is lower and self-discharge is higher.