As the energy storage sector shifts its focus from rapid expansion to a more sustainable, high-quality development model, large-capacity battery cells have emerged as a central innovation driver. At the 17th Shenzhen International Battery Technology Exchange and Exhibition (CIBF 2025), BAK Battery unveiled its groundbreaking 688Ah large-capacity energy storage cell, which boasts an energy density surpassing 435 Wh/L.

Enhanced Efficiency and Cost Benefits

The BAK 688Ah single large cell supports an impressive system energy capacity of up to 6.9 MWh. By reducing component count by 20% and decreasing the system footprint by 20% compared to conventional 20-foot containers, this innovation results in an 8% overall system cost reduction. These improvements not only lower initial investment but also increase project viability by optimizing land usage.

Industry-Leading Durability and Long Life

The 688Ah cell is designed for longevity, offering a cycle life exceeding 12,000 cycles and a calendar life of over 20 years—matching the operational lifespan of photovoltaic power plants. This durability provides a sustainable and cost-effective energy storage solution throughout the life of a project, enabling operators to benefit from reduced costs and improved efficiency.

Uncompromising Safety and Stability

Ensuring safety is paramount in the design of the 688Ah cell. It successfully passes rigorous energy storage abuse tests, including overcharging, short circuits, thermal runaway, and minor penetration scenarios, without any risk of explosion or fire. Its exceptional high-temperature stability guarantees safe and reliable operation in challenging environments.

Innovative Structural and Material Advancements

In response to the growing demand for large-capacity cells, BAK Battery has pushed the boundaries of innovation in multiple areas:

• ● Structural Design: The cell features a mature wound laminated architecture that optimizes manufacturing efficiency and performance. This structure reduces internal impedance, controls temperature rise, and improves heat dissipation, resulting in better safety and consistent temperature management.

• ● Materials: The cathode uses high-stability, high-density lithium iron phosphate (LiFePO4) for excellent cycling performance. The anode incorporates long-life, single-particle graphite. Combined with a proprietary, high-stability, long-cycle, high-temperature electrolyte and functional additives, these materials enhance capacity, cycle life, rate capability, and safety.

Driving the Future of Energy Storage

As the world transitions to a new energy landscape, energy storage remains a key enabler of the next-generation power system. With increasing demand for high-capacity cells from energy storage integrators, BAK Battery is dedicated to driving continuous technological and product innovations to propel the energy storage industry’s high-quality growth in this new era.