This Small Business Innovation Research (SBIR) Phase II project is poised to introduce superior electrolytes to the lithium-ion batteries by using a new class of low-cost, high-performance lithium salts. Currently, the cost of batteries is impacted not only by the high cost of the lithium salts, but also their relatively lower stability that limits battery lifetime. If successful, these electrolytes, to be developed under this Phase II project, will possess higher ionic conductivity and superior thermal and electrochemical properties that will be very attractive particularly for full size lithium-ion batteries applicable to electric vehicles and hybrid electric vehicles (EV/HEV). Building on the company's earlier success in developing a novel two-step synthetic strategy to prepare these salts which contain two lithium ions versus one in currently used salts, this project will optimize and scale up the synthetic process leading to the production of these salts at much lower cost, while meeting all principal specifications, including high transference number, an attractive property of a battery to function properly at subzero temperatures. This project will also further explore synthetic approaches to deliver even lower cost to capture the small size lithium battery market, where the applications are in computers, cell phones, cameras, and medical devices.
The broader/commercial impact of this project will be in the area of the rechargeable battery industry, especially in the arena of EV/HEV. Cost, performance and battery life are major drivers of this industry. The availability of electrolytes of lower cost, high performance and enhanced stability will contribute to cost reduction needed to make battery driven applications more affordable to users. The successful outcomes of this project are expected to contribute to the US Government's emphasis on renewable energy and particularly, the Department of Energy's roadmap on advanced batteries with more robust and stable chemistries and cost effectiveness.
Product Overview: Despite the success of current Li-ion battery technology in small scale applications (e.g., cellphones, laptops and tablets), factors such as high cost and short cell life present substantial roadblocks in producing an economically viable energy source for electric vehicle (EV), hybrid EV (HEV) and plug-in hybrid (PHEV) homologs. Technical challenges related to achieving this goal lie in the inability of currently existing technology to strike a balance between cost and performance. This has been especially true for Li-ion battery electrolytes (the second most expensive component after cathode materials), where often the lithium salt possesses the desired performance but is prohibitively expensive to manufacture. It is also clear that many commonly used, cost-effective, electrolyte materials degrade quickly and were developed for use in devices with an effective life of only 3-5 years-whereas the effective life of a vehicle is expected to be more than 15 years. To overcome these obstacles, and to secure a long-term alternative to petroleum fuels, TechDrive introduces a series of electrolytes that not only meet the high performance requirements, but also provides the economic viability to be viewed as a genuine alternative energy source. The electrolytes are obtained by mixing a novel low lattice energy lithium salt with various concentrations of a variety of organic solvents to cater to the needs of a wide range of applications. Unlike traditional lithium salts, which contain one lithium ion per molecule (i.e., mono-lithium salt), this salt contains two lithium ions connected to a single, large anionic species. These new electrolytes exhibit several characteristics superior to those of commonly used electrolytes, viz. high ionic conductivity, very good electrical and thermal stabilities, high cationic transference number, and strong resistance to corrosion of the aluminum current collector. The combination of these properties, coupled with the relatively lower cost and long shelf-life, offers manufacturers a competitive alternative to current state-of-the-art battery electrolytes. We are very optimistic that the availability of this novel salt to the battery manufacturers will significantly advance Li-ion battery technology. A patent application is being filed to aggressively pursue the commercialization of this product. Key Features: Outstanding solubility of the salt in carbonate and most other organic solvents. Electrolytes exhibit excellent ionic conductivity, electrochemical and thermal stability. High cationic transference number (near 0.6). Much greater resistance than LiTFSI to corrosion of aluminum current collector. High thermal stability of the salt. Applications: These products are useful for high efficiency primary and secondary lithium cells using organic liquid and polymer electrolytes, especially suitable for high power density batteries required for next generation communication devices (4G/5G cell phones) and electric vehicles.
