Lithium batteries use metallic lithium as their anode components. These batteries are commercially available in many chemistries to meet a variety of performance needs. One of the most common types for industrial and niche consumer applications is lithium thionyl chloride batteries. This type of battery is an ideal option for low power consumption applications. With their durability and long shelf life, lithium thionyl chloride batteries offer considerable advantages over other types of lithium batteries.
What Is a Lithium Thionyl Chloride Battery?
Lithium thionyl chloride (LiSOCl2) batteries are a type of lithium primary cell battery. Unlike lithium-ion or lithium-polymer batteries, they cannot be recharged. However, lithium thionyl chloride batteries offer an impressive lifespan, often working for several months or even years before needing replacement.
Lithium thionyl chloride batteries come in sizes that range from ½ AA to D cells. They are suitable for operating temperatures between -60 °C and 85 °C (-76 °F and 185 °F) and continue to deliver consistent high voltage even on the lower end of this temperature range.
These batteries can be produced using one of two possible construction methods: spiral-wound or bobbin. While each method has its advantages, the bobbin-type cell construction is the most common.
Bobbin-constructed lithium thionyl chloride batteries deliver currents up to 2 amperes and are ideal for long operating cycles and low-pulse applications, such as in gas meters. Bobbin-type batteries can be used with a hybrid layer capacitor for two-way wireless communications. Spiral-wound battery construction is used in applications that have high pulse requirements, such as RF transmitters.
Lithium Thionyl Chloride Battery vs. Lithium-Ion
Lithium thionyl chloride batteries are non-rechargeable batteries that are used in many industry-diverse applications. Although lithium-ion batteries are rechargeable, lithium thionyl chloride batteries offer several advantages over lithium-ion and other lithium battery chemistries, including:
- Higher voltage capacities: Typically, primary lithium cells offer cell voltages ranging between 1.5 and 3 volts. However, lithium thionyl chloride cells can deliver constant voltages of 3.6 volts over nearly the entire discharge period.
- Greater energy density and lower weight: These batteries can achieve energy density values up to 710 watt-hours/kilogram in a smaller and lighter package.
- Wider operating temperature range: Lithium thionyl chloride batteries can operate in temperatures between -60 and 85 °C.
- Better durability and longer shelf life: Lithium thionyl chloride batteries undergo a chemical reaction between the lithium anode and the electrolyte that forms a protective film over the anode. This film stops the flow of ions between the anode and cathode, resulting in a self-discharge rate of only about 1% per year and up to 10 years of operating life.
- Broader selection of options: Lithium thionyl chloride batteries come in many designs and sizes. The bobbin-type cell construction is frequently used since it is safe and long-lasting.
- Self-discharge rate: Lithium thionyl chloride batteries have an extremely low self-discharge rate. This allows them to maintain a charge for years without any required maintenance. They are an ideal choice for applications that require reliable power for extended periods, like medical devices, utility meters, or emergency lighting and alarm systems. In comparison, lithium-ion batteries have a moderate self-discharge rate. When not in use, they gradually lose their charge. However, the rate at which this occurs is relatively low.
Lithium Thionyl Chloride Battery Chemistry
Unlike lithium thionyl chloride batteries, lithium-ion (Li-ion) batteries use lithium as the anode and can feature a variety of cathode materials, including:
- Lithium cobalt oxide (LiCoO2)
- Lithium iron phosphate (LiFePO4)
- Lithium manganese oxide (LiMn2O4)
Lithium-ion batteries utilize a lithium salt that has been dissolved in an organic solvent as the electrolyte.
In contrast, lithium thionyl chloride (LiSOCl2) batteries use lithium as the anode and thionyl chloride as the cathode. Their electrolyte is lithium tetrachloroaluminate (LiAlCl4). This chemistry creates a different chemical reaction compared to lithium-ion batteries.
Lithium thionyl chloride batteries have a much higher energy density than lithium-ion batteries. Energy density is closely linked to capacity—the higher a battery’s energy density is, the more charge it can store within a given mass or volume. Lithium thionyl chloride batteries’ impressive energy density and capacity make them ideally suited for applications that require long-lasting, reliable power.
Common Applications of Lithium Thionyl Chloride Batteries
Due to their numerous advantages, lithium thionyl chloride batteries are used in many industrial and commercial devices and systems, such as:
- Cash registers
- Electronic toll collection (ETC) systems
- Electronic utility meters (e.g., for electricity, gas, and water)
- Failure analysis instruments (e.g., measurement instruments, onboard microcomputers, sensors)
- Fire/smoke alarms
- Medical instruments (e.g., automatic external defibrillators)
- Office automation machines (e.g., copiers, fax machines, printers)
- Two-way wireless communication systems
- Aerospace and defense applications
- Automotive electronics
- Emergency backup systems
- Oil and gas exploration
- Underwater instruments
Why Use H&V’s Lithium Thionyl Chloride Separators?
H&V’s separators are stable and used in batteries to promote a long life. The benefits of our lithium thionyl chloride battery separator include:
- Low impurities: Our paper products have little to no metals, contaminants, or chemical impurities. They are nonreactive.
- Lightweight: Our separator is a lightweight material at just 30-35 gsm. Pasting paper won’t significantly add to the thickness or weight of the assembly.
- Optimal battery performance: The separator does not interfere with other substrates in the battery assembly. It can be used for low or high rate discharge in the application.
Learn More About Lithium Thionyl Chloride Batteries From H&V
Lithium thionyl chloride batteries are used to power various devices and systems across different industries and applications. At Hollingsworth & Vose, we make advanced battery separator materials for lithium thionyl chloride batteries. These materials act as electron insulators; they isolate the electrodes while allowing ions to pass between them, which helps prevent short-circuiting.
To learn more about lithium thionyl chloride batteries and how our materials are used in them, contact us today.