some ideas

This is what my "friend" came up with. It should be in order of most commly sold items that are under 50usd ish, and would show off your battery.
Simple & Everyday Applications:

High-Power LED Flashlight: Showcase extended runtime compared to traditional batteries.
Wireless Charging Pad: Demonstrate fast charging capabilities. (Simple design with coil and indicator light)
Portable Phone Charger: Highlight compact size and long-lasting power for on-the-go users.
Bluetooth Speaker: Emphasize long playtime for music lovers.
Smartwatch: Focus on extended battery life for all-day wear.
Wireless Keyboard/Mouse: Demonstrate reliable power for a clutter-free desk.
Travel Alarm Clock: Highlight portability and long-lasting power for trips.
Toy Car with Remote Control: Showcase power and speed with extended playtime.
Headlamp: Emphasize long-lasting light for outdoor enthusiasts.
Miniature Fan: Highlight power efficiency for keeping cool on the go.
Educational & Interactive Projects:

Science Fair Project: Design a kit to demonstrate battery chemistry concepts with your new technology. (Combine with LEDs, motors, etc.)
DIY Soldering Kit: Create a basic circuit with your battery and LEDs for a fun learning experience.
Miniature Light Show: Showcase the power of the battery by powering a small LED circuit with various light patterns.
Interactive Science Exhibit: Develop a display that showcases the charging and discharging cycles of your battery with visual aids.
Creative & Unique Applications:

Wearable Mood Light: Design a small, decorative light powered by your battery that changes color based on mood.
Smart Plant Waterer: Create a device with a sensor that automatically waters plants, powered by the new battery.
Portable Phone Projector: Develop a compact projector powered by the battery to project phone content on a wall.
Miniature Weather Station: Design a device that collects and transmits basic weather data, powered by the new battery.
Emergency Phone Charger (Hand Crank): Combine your battery with a hand crank mechanism for emergency charging.
Solar Phone Charger (Miniature): Showcase the potential for renewable charging by integrating a small solar panel with your battery.
Focus on Specific Benefits:

High-drain Application: Power a device with high power needs (small motor, bright LED) to show extended life.
Fast Charging Application: Design a project that charges quickly using your battery technology.
Lightweight & Compact Design: Create a project that emphasizes the portability of the new battery.
Extreme Temperature Performance: Showcase the battery's functionality in hot or cold environments (within safe limits).
Long Shelf Life Demonstration: Develop a project that highlights the extended storage life of the new battery compared to traditional options.