Understanding the Intrinsic Limits of Ultra-Fast Charge Batteries

The holy-grail of batteries is to achieve a high energy density while being able to rapidly charge and discharge the battery within minutes. This will enable the more widespread adoption of electric vehicles, and design of other rapidly chargeable consumer electronics. It is often believed that charge rate is limited by an intrinsic material limit, however we demonstrate that the ultimate dominating limit is diffusion related. This is a challenge that can be addressed by careful system engineering. This presentation looks at a simple model of a battery and breaks the charge/discharge rate limitations into the key components, identifying the key factors to designing a fast-charge battery. Specific design methodologies are proposed, and several real-world chemistries are introduced to demonstrate the challenges in real terms.