Sony has detailed development of an energy storage module using lithium-ion rechargeable batteries made with olivine-type lithium iron phosphate as the cathode material. Key features of olivine-type lithium iron phosphate cell include high power output, long-life performance and excellent thermal stability. Sample shipments of the new module are scheduled to begin from June, 2010. The newly-developed module is an energy storage module with 1.2kWh-class capacity. Multiple modules can be connected either in series or in parallel to easily expand to a higher voltage or capacity. Furthermore, the new module is compatible with stationary power supplies such as UPS (uninterruptible power supply) for data servers or as a backup power supply for mobile phone wireless base stations.
In recent years, there has been an increasing demand for lithium-ion rechargeable batteries, which boast superior energy efficiency, higher power density and excellent storage characteristics, as substitutes for batteries made from lead or nickel-cadmium. Until now, lead-acid and nickel-cadmium batteries have conventionally been used in the stationary power supply market for data server UPSs (uninterruptible power supplies) or as backup power supplies for mobile phone wireless base stations.
Additionally, new applications of lithium-ion rechargeable batteries – such as energy storage systems for efficient energy use and load-leveling – continue to be developed as the installation of new energy generating systems like household photovoltaic systems progresses as part of environmental measures to reduce CO2 emissions.
Variables such as the voltage and capacity can be customized for different applications by connecting multiple modules either in series or in parallel. Each module is compatible with a high power output maximum of up to 2.5kW, and can be used for various stationary power supplies such as UPS (uninterruptible power supply) for data servers or as a backup power supply for mobile phone wireless base stations. A built-in self monitoring function for detecting any abnormalities within the energy storage module.
Internal battery usage can be controlled safely by monitoring the state (voltage, current, temperature) of the internal batteries and communicating this to a linked external battery management system. Another feature derived from the excellent thermal stability provided by olivine-type lithium iron phosphate cell is that the batteries should resist irregular heat generation, even in the event of a battery abnormality occurring for any given reason.
In comparison to lead-acid batteries, lithium-ion batteries have minimal energy loss when discharging the stored electrical energy. In other words, the charge and discharge of lithium-ion batteries is highly efficient, and demonstrative of the benefits of low energy consumption. Longer-life performance (anticipated longevity of 10 years or more), with estimated useful life based on one charge-discharge cycle per day. Iron (lithium iron phosphate), which is said to be available in abundance, is used as the electrode material. This enables reduced environmental impact in comparison to lithium-ion rechargeable batteries that use rare metals with extremely limited reserves and that are in low supply.
No regular maintenance is required such as rehydration, which is needed for some lead batteries. The energy storage moduleompatible with 19-inch (2U) size for mounting on standard computer server racks.
