Lithium Battery vs Alkaline Battery

Alkaline batteries contain zinc and manganese dioxide inside, with potassium hydroxide used as the electrolyte. Lithium batteries use graphite as the anode material, with the cathode potentially being lithium cobalt oxide, lithium iron phosphate, or ternary materials, and the electrolyte is a lithium salt solution.

In terms of voltage, a single alkaline battery cell is 1.5 volts. Lithium batteries vary by type—disposable lithium iron batteries are also 1.5 volts, while lithium-ion battery cells are 3.6 to 3.7 volts. Energizer's AA lithium battery can reach about 1.7 volts at no-load voltage, stabilizing around 1.5 volts when connected to a load.

Alkaline AA battery capacity is generally 1,700 to 3,000 milliamp-hours. Lithium-ion 18650 battery capacity is 1,800 to 3,500 milliamp-hours, with voltage more than double, resulting in energy that differs by several times when calculated. A single AA alkaline battery is about 3 watt-hours, while a single 18650 lithium battery can reach 11 watt-hours.

Alkaline batteries experience continuous voltage drop during discharge, from 1.5 volts down to 1.2 volts or even lower. Lithium batteries are different—their voltage basically stays within a range and only drops noticeably when nearly depleted. This is quite important for devices that require stable voltage.

The difference is even greater during high current discharge. When alkaline batteries discharge at 800 milliamps, the actual usable capacity may only be a little over 1,000 milliamp-hours. Lithium batteries under the same conditions can still maintain around 3,500 milliamp-hours.

Alkaline batteries perform poorly in low temperature environments. When temperatures reach below zero, voltage drops significantly and chemical reactions slow down. Lithium batteries can operate normally at minus ten-something degrees Celsius. Someone used lithium batteries to power a driveway alarm in an area where temperatures reached minus 30 degrees Celsius, with no problems.

Alkaline batteries have long storage times and can be stored for ten years without problems. Lithium batteries can be stored for twenty years. Alkaline batteries have faster self-discharge than lithium batteries.

In terms of weight, lithium batteries are approximately 30% lighter.

Alkaline batteries are cheap, with a single AA costing approximately $0.50 to $1. A single lithium-ion rechargeable battery costs $5 to $10. Alkaline batteries are discarded after use, while lithium-ion batteries can be recharged thousands of times. Lithium iron phosphate and lithium titanate cycle life can reach 10,000 times, with 90% charging efficiency.

Alkaline batteries have a risk of leakage. Old batteries stored for a long time often leak, corroding the device. Lithium batteries are better in this regard.

Alkaline batteries are suitable for remote controls, clocks, flashlights, and other low-power devices. Lithium batteries are used in mobile phones, cameras, power tools, electric vehicles, and medical equipment.

Regarding recycling, alkaline batteries are basically disposable and go into the trash after use. Over 90% of the materials in lithium batteries can be recycled and reused.

Some device manuals specify that only alkaline batteries should be used—switching to lithium batteries may cause problems. Higher voltage can shorten component lifespan. Check the manual before making any changes.