Smart Microfluidics Towards Low-Cost High-Performance Li-Ion Batteries

The cost of Li-ion batteries (LIBs) is presently the largest barrier to the electrification of road transport. Battery pack cost needs to be halved to $125/kWh (USABC target) in order to get electric vehicles (EVs) ready for mass market penetration by 2040, thereby helping the UK to meet its legislated emission reduction target of 80% for 2050. Meanwhile, the energy and power density of LIBs also need to be significantly increased to reduce the consumers' range anxiety.

Transport in the electrolyte plays a key role in determining the cost, performance and lifetime of a LIB cell, and can be linked to all the above key barriers to mass EV adoption. Particularly, transport in the electrolyte has been found to become the major limiting mechanism to the high-power operation of LIBs, as well as to the pursuit of thick electrodes which is being widely considered as a near-term solution to energy density increase and cost reduction for EV batteries. However, the present LIB designs with static electrolytes provide little room for improving and engineering the electrolyte-side transport processes. Therefore, radical innovations in the engineering design of LIB cells are urgently needed to address the electrolyte-side limitations to meet ever fast increasing performance of electrode active materials.

Relying on the unique features of microfluidics including easy integration, rapid heat and mass transfer and precision control, this Fellowship aims to develop a novel microfluidic-based approach to engineering the transport processes in the electrolyte of LIBs, with the goal of improving cell energy and power density and reducing cost. To achieve this aim, the Fellowship will first combine integrated microfluidics and fluorescence microscopy to develop an easily accessible, multiscale, multichannel tool for characterising the coupled thermal-hydro-electrochemical dynamics and its interplay with electrode microstructures in a LIB cell during operation, underpinning further technological innovations. The Fellowship will then conduct a systematic model-based parametric study to develop directional microfluidic designs for LIB cells and to develop microfluidic principles for manipulating the fluid flow, local composition, temperature and electrochemical processes in the new cell design for optimal performance. The Fellowship will finally explore high-efficiency upscaling strategies for the new cell design and analyse their economic feasibilities for EV applications.

The Government's ambition to have all new vehicles zero carbon emissions by 2040 has made the current decade a crucial period for electric-vehicle (EV) market uptake. The microfluidic approach developed in the Fellowship can potentially provide a near-term solution to the key technical barriers to widespread EV adoption, and facilitate high EV uptake. Following the high uptake pathway, the Government has forecasted that >10 million EVs will be on UK roads by 2030, which is estimated to bring about 50% carbon reduction, 51% reduction of foreign oil imports and 320k new jobs. According to the KPMG report, the overall economic and social benefit of EVs, connected and autonomous vehicles to the UK economy is of the order of £51bn per year by 2030. This Fellowship will also contribute to keeping the UK at the forefront of novel battery technologies by establishing the scientific and technical principles underpinning the rational design of next-generation, lower-cost, higher performing batteries.

The Fellowship will directly impact on UK companies in both the Li-ion battery (AGM Batteries, PV3, WMG) and flow battery (WhEST) industries. These industry stakeholders will participate in the Fellowship program as partners. Close and effective collaborations with the industrial partners will be ensured in the Fellowship through in-kind contributions, Advisory Board involvement, secondments and workshops. As the research progresses, I plan to attract more industrial partners beyond the existing partnerships through industrial-oriented outreach activities to deliver an early impact on the automotive and energy industries. Key stakeholders will include automotive manufacturers, renewable energy service providers and the Government. Besides, I will catalyse 'business-business collaboration' between the battery makers and battery users to further accelerate the commercialisation of the new battery technologies.

The Fellowship is expected to generate patentable IPs in two areas. Firstly, the new microfluidic characterisation platform is a powerful easy-to-access tool to underpin the design and manufacturing of Li-ion battery materials and devices, and thus of a high commercial value to the battery manufacturers. Secondly, the proposed low-cost high-performing microfluidic flow-through Li-ion design will impact on both the Li-ion battery manufacturers and users (e.g., automotive industry). Moreover, it can also open up new business opportunities for the flow battery industry. Though the proposed innovations are ultimately targeted at the EV industry, they will also benefit other end users. In a longer term, I aim to follow the successful business models by the university spinoffs in the field such as 24M (a spinoff company from MIT) and NanoFlowcell (a spinoff company from ETH) to capture IPs, attract industrial interests and investments, and exploit the market.