As smart cards become more sophisticated integrating displays, sensors, dynamic authentication modules, and even microprocessors the challenge of powering them sustainably has become increasingly urgent.
Most advanced cards today rely on thin lithium batteries, either primary or rechargeable cells embedded inside the laminated structure of the card.

However, these batteries present several major challenges:

1. Regulatory and logistical constraints:

Products containing lithium batteries face strict transportation regulations, which significantly increase shipping complexity and cost.

2. Environmental impact:

Producing and recycling lithium batteries consumes substantial energy and generates non-negligible environmental impact.

3. End-of-life limitations:

In most smart cards, the battery is inaccessible and cannot be replaced. Once depleted, the entire card must be discarded and manufactured again or designed with a charging interface, which adds cost and reduces efficiency.

A typical smart card is expected to last up to15 years, yet an internal primary cell battery often lasts less than two. As a result, a single user may go through 7–8 cards, discarded solely because their embedded battery ran out of power, unless the card is designed with a rechargeable battery requiring charging hardware. This can create significant electronic waste and increases the carbon footprint.

For example, an ultra-thin rechargeable battery with smart-card-compatible dimensions (55.5 × 22.5 × 0.5 mm), such as the GRP0422055, can deliver approximately 333 joules of total stored energy (4.2 V × 22 mAh).
A typical smart card requires around 0.068 J per activation, meaning this battery supports only ≈4,897 activations in ideal conditions.

Given that users activate their cards 5 to 60 times per day, the battery lifetime ranges between:

• Best case: ~979 days
• Worst case: ~81 days

Far from the up to 15-year lifespan expected from a modern smart card.

Organic Photovoltaics: A Transformative Alternative

Organic photovoltaics (OPV) offer a promising and sustainable solution.

These ultra-thin, flexible solar cells can be seamlessly integrated into the card and harvest energy even under low-intensity indoor lighting. Under typical indoor illumination 200 lux for 10 hours per day a 10.5 cm² OPV module can produce over a 15-year period:

5.775 Wh, equivalent to 20,790 joules, which corresponds to ≈ 63 times the energy stored in the 22 mWh battery mentioned earlier.

This output enables the card to function even under heavy usage for up to 14 years, without relying on a conventional lithium cell. Instead of a disposable battery, energy storage can be provided by an ultra-slim supercapacitor, which is smaller, safer, and rated for over 100,000 charge cycles.

As OPV alone cannot cover every scenario, smart cards must remain fully functional even for days or weeks without exposure to light. To maintain essential security functions during these dark periods, the card must include a small amount of backup energy storage. Ultra-slim supercapacitors are ideal for this purpose as:

• they are available in sub-millimeter thickness,
• they withstand thousands of cycles without degradation,
• and they integrate easily within the card’s lamination.

With a properly dimensioned OPV surface and a thin supercapacitor, the card’s energy reserve never fully depletes, enabling a single card to last 14+ years instead of being replaced every 1–3 years due to battery exhaustion.

This new solution represents a sustainable breakthrough for the smart-card industry, as it dramatically reduces electronic waste, simplifies logistics and shipping (no lithium restrictions), lower carbon emissions and far more sustainable product lifecycle

OPV-powered smart cards with integrated ultra-slim supercapacitors represent a practical, clean, and scalable evolution in secure, connected card technology—powering devices with nothing more than everyday indoor light.