Sodium-ion battery

Sodium-ion batteries (SIB) are a type of rechargeable metal-ion battery that uses sodium ions as charge carriers. Sodium-ion batteries (SIB) are a type of rechargeable metal-ion battery that uses sodium ions as charge carriers. Battery-grade salts of sodium are cheap and abundant, much more so than those of lithium. This makes them a cost-effective alternative especially for applications where weight and energy density are of minor importance such as grid energy storage for renewable energy sources such as wind- and solar power These cells can be completely drained (to zero charge) without damaging the active materials. They can be stored and shipped safely. Lithium-ion batteries must retain about 30% of charge during storage, enough that they could short-circuit and catch fire during shipment. Moreover, sodium-ion batteries have excellent electrochemical features in terms of charge-discharge, reversibility, coulombic efficiency and high specific discharge capacity. In 2014 Aquion Energy offered a commercially available sodium-ion battery with cost/kWh capacity similar to a lead acid battery for use as a backup power source for electricity micro-grids. According to the company, it was 85 percent efficient. Aquion Energy filed for Chapter 11 Bankruptcy in March 2017, but is resuming operations again in 2018. In 2015 researchers announced a device that employed the '18650' format. 18650 is a battery form factor commonly used in laptops, LED flashlights and the Tesla Model S, among other products. Its energy density was claimed to be 90 Wh/kg, a performance comparable to lithium iron phosphate battery. In 2016 other researchers announced a model for a device that used symmetric manganese dioxide electrodes in a saltwater bath, separated by a membrane that allowed Cl- to cross it. While charging, Na+ ions intercalated into the electrode on one side and Cl- ions migrated across the membrane, reducing salinity by 63%. While discharging, the Na+ ions left the electrode on one side while other Na+ ions entered it on the other side. In November 2017 French Network on Electrochemical Energy Storage (RS2E) announced the intention to produce a 18650 format cell by 2020. The cell will be 3.5V, 90Wh/kg, perform more than 2,000 charge and discharge cycles without significant loss of performance, and life expectancy of more than 10 years in continuous use. In June 2019 the California Energy Commission awarded $3 million to install a sodium-ion battery with Prussian blue.