The passport you carry to travel from one country to another not only serves to prove your identity but also allows international authorities to query and verify information about you from multiple databases. A physical passport is nothing but a presentation of data points that customs officers use to confirm your identity when deciding whether to permit you to cross a certain border. In order to make international travel more seamless, countries often work together to standardize the format and contents of the physical passports issued to residents.

Similarly, a battery passport is nothing but a presentation of data points about a particular battery – who manufactured it, its physical and chemical composition, its current state of health, whether it was refurbished or repurposed from another battery, and so on.

The battery passport has many uses. For example, regulators can reference a battery passport to verify whether that particular battery is composed of an adequate proportion of recycled material. Likewise, battery passports enable battery owners to query their battery’s state of health.

Battery passports can be implemented as a barcode or QR code or in RFID chip the same way our travel passports are equipped with barcodes or long strings of alphanumeric characters, similar to the Battery Identification Number Standard released by MOBI in July 2022.

The barcode or QR code on a battery passport needs to retrieve information about the battery from some digital source. That digital source about the battery can be either a centralized location maintained by some entities or in the battery itself or some combination thereof. This is not very different from the fact that our travel history, medical records, etc. are stored in databases mostly maintained by governments.

This is where Battery Self-Sovereign Digital Twin™ (SSDT™) comes in.

Battery Self-Sovereign Digital Twin Digital Storage for Battery Information

The battery SSDT is where the information about a battery resides. Conceptually, the battery SSDT can store and receive information about the battery from outside sources, respond to internal and external queries, and verifiably assert its identity and the information it stores/presents. What is unique about the battery SSDT is that an outside issuing entity is not required, unlike travel passports that are issued by our governments. Because the battery SSDT leverages self-sovereign identity, the battery can assert its own identity with the help of an external trust anchor.

The battery SSDT includes information about the battery’s owner, birth certificate, material and component attributes, maintenance history, warranty and recall logs, charging history, state of health, and may even have the capability to issue payments for services performed on the battery.

Battery SSDTs are onboarded and managed via Citopia, a federated Web3 marketplace for business automation and trustless multiparty track-and-trace.

The controller of the battery SSDT can participate in seamless transactions (including data sharing) by issuing Verifiable Credentials (VCs) and Verifiable Presentations per W3C’s VCs Standard. Citopia leverages zero-knowledge proofs and other advanced cryptographic methods to give users control over who sees their data and how that data is used.

SSDTs on Citopia are linked to a trust anchor such as the Integrated Trust Network (ITN) using Decentralized Identifiers (DIDs) per W3C’s DIDs Standard. Both Citopia and the ITN are member-owned and operated.

The Battery SSDT is Key to Battery Traceability

Traceability of battery origin, production, usage, recycling/repurposing, and more is vital to ensuring compliance with various regulatory requirements (e.g., EU Battery Regulation, CARB), meeting environmental and social goals, improving warranty management, and many more. The battery SSDT provides information about the battery to a third party using the Battery Passport as a credential. In addition to holding the physical attributes of the battery, the battery SSDT also stores traceability-related data in its encrypted data vault. Because traceability data will come from multiple sources (entities), the battery SSDT will ensure the verifiability of such data by linking the identity of the entities to a trust anchor.