**Clearly define the application scenario**
- **Portable devices**: e.g. mobile phones, notebook computers, digital cameras, etc., which usually require high energy density and lightweight batteries (e.g. lithium-ion batteries).
- **Electric transport vehicles**: e.g. electric vehicles, electric bicycles, which require batteries with high energy density, long cycle life and high safety (e.g. lithium-ion batteries or solid-state batteries).
- **Energy storage systems**: such as home energy storage, grid peaking, requiring low-cost, long-life and high-safety batteries (such as sodium-ion batteries or lithium iron phosphate batteries).
- **Industrial equipment**: e.g. power tools, drones, requiring batteries with high power output and fast charging capability (e.g. lithium polymer batteries).
- **Backup power supply**: e.g. UPS (Uninterruptible Power Supply), requiring batteries with high reliability and long cycle life (e.g. lead-acid batteries or lithium iron phosphate batteries).