To reduce climate change and local pollution the combustion engine must be replaced by an electric drivetrain supplied by safe, high energy density, high power density, and long-life rechargeable batteries. The solid-state battery (SSB) uses inflammable solid-electrolytes that are inherently safe, and Li-metal anodes and high voltage cathodes that are inapplicable in conventional liquid electrolytes for high energy density. However, SSB manufacturing is immature and unsatisfactory, with its problems including: (i) vapour processing for the anode that is uneconomic, (ii) traditional casting for the cathode that does not transfer to SSBs, (iii) uncertainty how to manufacture interfaces between the materials used in a SSB cell that can withstand the expansion/contraction during battery charge/discharge; and (iv) multiple, time consuming assembly steps.

New ideas for manufacturing solid state Li ion batteries will be investigated using additive manufacture and 3D printing to produce improvements in one or more of energy density, power density, cycle life, and reduced cost of SSBs.

Objectives/Aims
1. To explore the possible benefits of additive manufacture for the efficient, reduced step manufacture of SSBs.
2. To develop a flexible, generic layer-by-layer manufacturing approach for SSBs that allows micron-scale control of microstructure, including the local electrolyte, conductivity and binder fraction.
3. To investigate the relationship between SSB through-thickness design, manufacture and performance using 3D sectioning and reconstruction techniques and electrochemical testing, and to quantify any benefits in terms of best-in-class industrial manufacturing approaches.

What questions will addressed
What beneficial role can additive manufacture have for the production of assembly-free SSBs; which properties can be enhanced by through-thickness control and which properties are degraded compared with current best-in-class SSBs; do additive manufacture SSBs provide a different balance of properties across requirements that opens up new niche or mass market opportunities.

Novelty of the research methodology
The principal novelty is the use of an in-house, patented layer-by-layer additive manufacturing approach for electrochemical electrodes and cells that allows micron-scale microstructural control. This approach allows fast iteration of microstructural design, make and test cycles. Numerical modelling will be used to guide the design process.

Impact and application
Successful development of the layer-by-layer process and SSBs will generate intellectual property and patent applications followed by publications in high impact peer reviewed journals. The work is closely aligned with Faraday Institution programme of solid state batteries (SOLBAT) and good industrial links offer a credible pathway to impact of research findings in electric vehicles and grid storage.

This project falls within the EPSRC Energy and Manufacturing the Future research areas.