Energy storage is absolutely crucial in today’s world. More than just the batteries in our remote controls, more even than our mobile phones and laptops; advancements in energy storage could solve the issues with renewable power,  preserving energy generated at times of low demand.

Advances in lithium-ion batteries have dominated the headlines in this area of late, but a variety of developments across the field of electrode materials could become game changers.

1. In the beginning, there were metals

 

The Daniell cell, an early battery from 1836 using a zinc electrode. Image: Daderot

Early batteries used metallic electrodes, such as zinc, iron, platinum, and lead. The Daniell cell, invented by British chemist John Frederic Daniell and the historical basis for the volt measurement, used a zinc electrode just like the early batteries produced by scientists such as Alessandro Volta and William Cruickshank. 

Alterations elsewhere in the Daniell cell substantially improved its performance compared with existing battery technology and it became the industry standard.

2. From acid to alkaline

 

Waldemar Jungner: the Swedish scientist who developed the first Nickel-Cadmium battery. Image: Svenska dagbladets årsbok 1924

Another major development in electrode materials came with the first alkaline battery, developed by Waldemar Jungner using nickel (Ni) and cadmium (Cd). Jungner had experimented with iron instead of cadmium but found it considerably less successful. 

The Ni–Cd battery had far greater energy density than the other rechargeable batteries at the time, although it was also considerably more expensive.

3. Smaller, lighter, better, faster

 

Organic materials for microbattery electrodes are tested on coin cells. Image: Mikko Raskinen

Want your electronic devices to be even smaller and lighter? Researchers from Aalto University, Finland, are working on improving the efficiency of microbatteries by fabricating electrochemically active organic lithium electrode thin films. 

The team use lithium terephthalate, a recently found anode material for a lithium-ion battery, and prepare it with a combined atomic/molecular layer deposition technique.

4. There’s more to life than lithium

 

50-70% of the world’s known lithium reserves are in Salar de Uyuni, Bolivia. Image: Anouchka Unel

Lithium-ion batteries have dominated the rechargeable market since their emergence in the 1990′s. However, the rarity of material means that, increasingly, research and development is focused elsewhere. 

Researchers at Stanford University, USA, believe they have created a sodium ion battery with the same storage capacity as lithium but at 80% less cost. The battery uses sodium salt for the cathode and phosphorous for the anode. 

5. Back to the start

Advances are also being made in the electrode materials used in artificial photosynthesis. Video: TEDx Talks

Hematite and other cheap, plentiful metals are being used to create photocatalytic electrode materials by a team of scientists from Tianjin University, China. The approach, that combines nanotechnology with chemical doping, can produce a photocurrent more than five times higher than current approaches to artificial photosynthesis. 

You can read an interview with the recipient of SCI’s 2017 Castner Medal, who delivered the lecture Developments in Electrodes and Electrochemical Cell Design, here.