Energy Storage Energy storage in 2020: Where is the industry headed?
Although lithium-ion has long since been hailed as the future of advanced batteries, the technology has several limitations and flaws that have encouraged manufacturers and researchers to consider alternatives as the world sits on the verge of a power revolution.
Lithium-ion batteries are responsible for the power behind your smartphone, laptop, and virtually any rechargeable device you own—automobiles like the Tesla even rely on them.
Despite its widespread use and its incredible history of success, however, lithium-ion batteries are not perfect. From high-profile fires to the rising cost of lithium, there are many reasons why experts are scrambling to find a safer, more efficient, and less expensive substance to power tomorrow's electronics.
Luckily, there are several other types of power storage solutions, and 2020 is the year where we will begin to see new energy storage technologies share the spotlight with lithium-ion.
Back to basics
Chemical batteries are made up of the same basic components, including two electrodes and some form of electrolyte. Rechargeable batteries draw energy through a chemical reaction that creates charged particles (ions) in the positive electrode (cathode). These travel through the electrolyte and into the negative electrode (anode) where they remain. When the battery is discharging, these ions travel back from anode to cathode to produce energy.
In a lithium-ion battery, the cathode is made from a compound that contains lithium and the negative electrode from carbon in the form of graphite. The electrolyte varies.
Lithium-ion batteries work well because they can go through many charge cycles without wearing out too much, have a high energy density, and don't take up much room. However, they also expand more than other batteries as they get warmer. And because batteries are filled with nasty chemicals, this is not an ideal characteristic. Unfortunately, this has been the culprit behind many high-profile battery-related incidents, some serious.
Creating cheaper, safer, long-term energy storage systems
The U.S. Department of Energy's Advanced Research Projects Agency (ARPA-E) is currently funding research by several different organizations with a shared goal: The creation of long-term energy storage systems that cost $0.05 per kW/h or less. After these projects are complete, ARPA-E plans to fund trials on a small scale to determine which are commercially viable and could be used to replace current lithium-ion tech.
Five of these projects are scheduled for completion this year, with a further five earmarked for completion by the end of 2021. The ARPA-E research is split into several general categories, including:
Sulfur flow batteries
A Somerville, Massachusetts start-up named Form Energy is working on sulfur flow batteries that it claims will permit "full-week backup capability at a factor of 10 times or greater, cheaper," Sulphur flow batteries boast the lowest chemical cost of all rechargeable batteries, however, they are relatively inefficient. To solve this, the company is working on new anode and cathode formulations, membranes, and a boost to the physical system.
United Technologies is also working under ARPA-E in partnership with Lawrence Berkeley National Laboratory, MIT, and Pennsylvania State University to research sulfur and manganese flow batteries.
Electricity to hydrogen
One solution that could be used when the supply of electricity exceeds demand is to use it to break water down into hydrogen and oxygen. In theory, the hydrogen produced can be used at a later date to make electricity in fuel cells; however, converting energy back and forth from one form to another is inefficient.
The University of Tennessee, Knoxville, is working to improve this efficiency by developing an advanced regenerative fuel cell. This device will function as both a fuel cell and an electrolyzer—a cell that achieves the electrolysis of water.
Zinc-bromine flow batteries
Primus Power already makes these batteries, but with ARPA-E funding, the company hopes to "eliminate the need for a separator to keep the reactants apart when charged," by "taking advantage of the way zinc and bromine behave in the cell."
Their current research centers around modifying the battery's configuration so that all the electrolytes can be stored in a single tank rather than multiple cells, thus reducing the hardware footprint required to complete a system.