High-performance batteries for renewable energy storage
In their bid to reduce carbon dioxide emissions, power companies have turned to renewable energy sources such as wind, wave and solar. However, the power supplied by these sources is intermittent, as it depends on external variables. Making renewable energy practical requires examining new methods of storing energy on a large scale and releasing it on demand. Li-ion batteries are able to provide uninterruptible power supply and high-quality power and distribution. The EU-funded project SIRBATT (Stable interfaces for rechargeable batteries) was a three-year collaboration between six universities and five private sector companies across Europe with the aim of radically improving understanding of the structure and reactions occurring at the interface of the battery electrode and electrolyte. Battery performance and durability are strongly influenced by the characteristics of the solid electrolyte interphase (SEI) that is rapidly formed upon the electrodes. Using different modelling and simulation techniques, researchers obtained further insight into SEI formation and transport properties of lithium metal and graphitic carbon anodes as well as the atomic and electronic factors governing the SEI formation and ageing mechanisms. Evolution of the SEI in the anode materials at selected charging steps was studied by exploiting the surface sensitivity of the soft X-ray absorption spectroscopy. A wide range of new ex situ and in situ measurement techniques helped researchers examine the chemistry of the bulk electroactive materials and their surfaces. The project team also synthesised a wide range of anode and cathode electrode materials and tested them in conventional and additive-containing electrolytes at different temperature and cycling regimes. Green electrode formulations via aqueous processing and use of a fluorine-free binder were a further project highlight. Newly developed microsensors will be used to monitor lithium cells to maintain optimum operating conditions and allow operation of long-life devices that can be scaled for use in grid-scale batteries. SIRBATT explored the issues that currently limit the lifespan of batteries used in stationary battery storage, seeking to provide a preventative solution to ensure the longer life of Li-ion batteries in the future.
Keywords
Batteries, renewable energy, energy storage, Li-ion, SIRBATT, solid electrolyte interphase
