Battery Saggar Material Testing and Screening for Improved Lifespan
Case study
Lithium-containing batteries, including lithium ion and solid state, are seeing an increase in use for applications such as electric vehicles and renewable energy storage. This is being matched by a corresponding increase in battery manufacture, and therefore manufacture of component parts and materials.
The challenge
Lithium-ion electrode materials are typically fired (or calcined) during processing to optimise battery performance. This operation is extremely harsh on the crucibles or saggars used to contain the powders. Traditional saggars do not last for many cycles before breaking and needing to be replaced. Broken saggars cannot be recycled, and due to lithium contamination, must be disposed of carefully. Saggar breakdown can also lead to contamination of battery powder, which increases wasteful scrap rates of valuable battery electrode materials. Identifying saggar materials resistant to lithium attack is therefore a priority, but would be time consuming and costly if full kiln loads need to be trialled in production.
What we delivered
Over 30 candidate saggar materials were immersion tested in lithium electrode simulant and then analysed through a range of tests including SEM, EDS, XRD to understand the mechanisms of lithium attack and identify suitable materials. A selection of the most promising was fully tested as mini saggars in an accelerated cycle testing regime which simulated kiln firing and enabled quick identification of the most suitable saggar materials. Chemical resistance and impact of microstructure on lithium resistance were investigated. Thermal shock and abrasion testing were used to understand the performance of the saggar materials further.
Value to the client
Combining refractories testing and deep materials and process knowledge, new saggar materials were identified that showed high resistance to lithium attack, potentially giving a lifespan of at least 5 times longer than standard saggars. Implementation of such saggar materials in battery powder materials manufacture could offer significant cost savings through both lower scrap rates of battery powders and less hazardous waste produced from failed saggars.