Overview
Lithium-sulfur (Li-S) is expected to be the next generation battery chemistry of energy storage systems. They are supposed to deliver highly specific energies, which are 2-4 times higher than current lithium-ion systems. Another advantage is that sulfur is a cheap and abundant resource and no expensive or even harmful metals are needed as is the case of lithium-ion cathodes (e.g. LiCoO2)
Novel materials such as nanostructured carbon/sulfur composite cathodes, solid electrolytes and alloy-based anodes are expected to significantly enhance the cell performance.
All the necessary steps for reaching this goal are considered, starting from material synthesis and characterization, exploiting nanotechnology for improving rate capability and fast charging, the fabrication and test of large scale prototypes and to the completion of the cycle by setting the conditions for the recycling process. A team of experts have been selected as partners of the project, including a number of academic laboratories, all with worldwide recognized experience in the lithium battery field, whose task will be that of defining the most appropriate electrode and electrolyte nanostructures.
The project is aimed to the identification and development of nanostructured electrode and electrolyte materials to promote the practical implementation of the very high energy lithium-sulfur battery. In particular, the project will be directed to the definition and test of a new, lithium metal-free battery configuration based on the use of lithiated silicon as the anode and a nanostructured sulfur-carbon composite as the cathode. It is expected that this battery will offer an energy density at least three times higher than that available from the present lithium battery technology, a comparatively long cycle life, a much lower cost (replacement of cobalt-based with a sulfur-based cathode) and a high safety degree (no use of lithium metal).
The project will benefit by the support of a laboratory expert in battery modeling to provide the theoretical guidelines for materials’ optimization. Large research laboratories, having advanced and modern battery producing machineries will be involved in the preparation and test of middle size battery prototypes. Finally, chemical and battery manufacturing industries will assure the necessary materials scaling-up and the fabrication and test of large batteries and particular attention will be devoted to the control of the safety and to definition and practical demonstration of its most appropriate recycling process.
1 - Management: Set-up of an efficient management structure with clear rules for decision-making and administrative support on financial and administrative matters.
2 - Scientific coordination: Ensuring the successful execution of the project by overseeing that project activities comply with planned activities and that deadlines for deliverables and milestones are respected.
3 - Modelling and simulation of the electrodes and electrode materials: Developing a well-founded scale-bridging model and subsequently a simulation of the performance and lifetime of sulphur-based battery cells. With this modelling and simulation approach it would be possible to optimise cell chemistry and electrodes design.
4 - Optimization of the electrolyte materials: Developing and optimizing new electrolyte solutions and nano structured polymer membranes for Li/S-batteries and investigation of the applicability of the new ceramic solid state electrolyte.
5 - Optimization of the electrode materials: Developing new nano structured configurations for anode and cathode materials.
6 - Optimization of the cell design: Optimizing the cell design for carrying out the electrochemical characterization of the materials.
7 - Scaling-up of electrode and electrolyte materials preparation: Scaling-up processes for electrolyte and electrode materials
8 - Scaling-up to large battery cell prototypes: Evaluation of the developed nano-structured components and cell configurations by assembling up-scaled Li-S cell prototypes.
9 - Test of performance and safety: Collecting and validating technical specifications for the Li-sulphur batteries performances and safety tests.
10 - Recyclability and life-cycle sustainability: Development of a recycling process for future lithium/sulphur batteries to recover high purity lithium salts and life cycle sustainability assessment.
11 - Dissemination and exploitation: Dissemination of project results in the relevant international forums and IPR management.
Funding
Results
Electric cars that go the distance
Lithium (Li)-ion batteries power mobile applications from laptops to cameras to electric cars. A new Li-sulphur battery that promises three times higher energy density could keep those products running significantly longer on a single charge.
A large European consortium is on the way to practical implementation of a very-high-energy Li-sulphur battery with EU financial support of the project 'Lithium sulfur superbattery exploiting nanotechnology' (http://www.lissen.eu/ (LISSEN)). The proposed battery configuration consists of a silicon (Si)-carbon composite anode and a nano-structured lithium sulphide (Li2S)-carbon composite cathode.
In addition to a major increase in energy density, the materials will support a comparatively longer life cycle at a much lower cost, the latter achieved by replacing cobalt with sulphur at the cathode. In addition, without Li metal, the battery will be much safer as well.
The consortium assembles a team of experts that are recognised global leaders in academic research and industrial manufacture of Li battery technology. The project covers all aspects from materials synthesis and characterisation to fabrication and testing of large-scale prototypes to recycling at end-of-service-life.
Within the first 18 months, the scientists made impressive progress towards their ambitious goals. 3D geometric models represent key materials properties such as particle distribution and porosity. They were instrumental in deriving chemical and physical parameters of bulk materials subsequently used in 1D Li-sulphur cell kinetic models.
All battery cell components are now in various stages of development. A safe and stable ionic liquid electrolyte mixture limits problematic sulphur cathode dissolution. Scientists also developed a nano-structured polymer electrolyte membrane that works efficiently in the Li-sulphur battery.
Two cathodes have been produced at lab scale. Carbon-coated Li2S particles are particularly promising and a patent is pending. Hollow carbon spheres are currently being optimised. Scientists have replaced the conventional reactive Li metal anode with an Si-carbon composite with promising electrochemical properties.
The electric car market is growing, but the driving range on a single charge must be extended to around 200 km or more to be truly appealing to consumers. LISSEN's Li-sulphur battery technology could provide the answer and, along with it, important benefits for consumers, the environment and the competitive position of the EU in a market on the verge of a breakthrough.