A team of Berkeley Lab researchers led by Gao Liu has developed a doping process for lithium ion battery electrode formation that can boost a cell’s charge capacity and lower its cost while improving reliability and safety.
Specifically, the Berkeley Lab team addressed issues with electrode formation by “pre-lithiating” both positive and negative electrodes with stabilized lithium metal powder (SLMP®) in a highly calibrated process. Doping graphite or silicon electrode materials with SLMP® gives manufacturers a high degree of control of the electric potential of the battery components, simplifying the electrode formation process and lowering costs. The direct introduction of lithium into anodes or cathodes, in a slurry fabrication process that mixes SLMP® with binders and active electrode materials such as silicon or graphite, reduces formation capacity loss and results in improved cycling capacity compared to that of batteries made with conventional processes.
Electrode formation is the most time-consuming step in the manufacture of lithium ion batteries. The process takes three to four weeks to complete, and accounts for roughly 20% of manufacturing costs. The charging and discharging required for this process also consumes substantial quantities of a battery’s lithium, causing a 10–50% capacity fade before a new battery leaves the factory.
In conventional lithium ion battery manufacturing processes, a graphite anode has no lithium in its initial fabrication stage, thus requiring that the cathode be highly lithiated at the start of the process. This limits the choice of cathode materials. The introduction of SLMP® into anodes leaves them partially or fully lithiated, opening up the possibility of using non-lithiated materials in the cathode.
Applications and Industries
- Rechargeable batteries for consumer electronics, cordless tools, etc.
- Hybrid and plug-in hybrid vehicles
- Simplifies and speeds up electrode formation process
- Reduces formation capacity loss
- Improves Li-battery cycle life and safety
- Lowers manufacturing cost