CALB unveils two high-capacity cells, aiming at long-duration energy storage
Source：ess-news
CALB has introduced two high-capacity lithium-iron-phosphate (LFP) cells – 588 Ah and 684 Ah – at its 2025 Global Partner Conference in Hefei, in a push to define the next phase of long-duration energy-storage technology. Both products, part of the company’s newly branded “Ultralife” series, represent its third-generation long-life storage technology and are scheduled to enter mass production in late 2025.
According to specifications released by CALB, both the 588 Ah and 684 Ah cells achieve a volumetric energy density of 450Wh/L, roughly 10% above the current industry average. The 588 Ah cell uses a mature winding process, designed for cost-sensitive grid and commercial projects, offering more than 10,000 cycles at 70% state-of-health.
The 684 Ah model adopts a more advanced stacking process, improving consistency and heat dissipation, and is rated for over 15,000 cycles, enabling full-lifecycle parity with 20-year photovoltaic projects – one of the key metrics driving global utility-scale tenders.
Both cells are positioned as “three-year zero-degradation” products, significantly outperforming the typical 3,000–5,000 cycles available in mainstream storage cells.
CALB highlighted several core innovations underpinning the two products. A lithium-supplementing mechanism embedded in the cell architecture compensates for long-term lithium loss, enabling stable capacity retention in early-life operation. Complementing this is an SEI self-repair mechanism that restores electrolyte–electrode interfaces during cycling, reducing active-lithium consumption and supporting extended lifetime cycling.
Safety architecture is another focus. Both cells incorporate the company’s TPP thermal-electric isolation, a dual-insulation system using ceramic composite materials capable of withstanding over 1,000°C, and a directional pressure-relief structure that prevents multi-point short-circuit events. CALB claims these features achieve “zero thermal-propagation,” a key requirement for large containerised systems.
The dual-route strategy allows CALB to target contrasting storage segments:
- 588Ah (wound): lower internal resistance, high production efficiency and cost stability; aimed at large solar-plus-storage sites, grid-frequency regulation and C&I installations.
- 684Ah (stacked): higher energy density and longer service life; positioned for long-duration storage, grid-support assets and remote microgrid applications.
Based on the new cells, CALB’s latest 6.25 MWh and 6.9 MWh containerised systems reduce component count by 30% and lower failure rates by 20%, while improving levelised cost of storage (LCOS) by 5–8%.
The new products extend CALB’s existing portfolio, which includes 314 Ah and 392 Ah cells, forming a tiered matrix suited to MWh- to GWh-scale systems. Executives at the conference noted that the company is seeing rising demand for long-duration, grid-level and solar-paired storage as renewable penetration accelerates in Asia, Europe and Australia.
The launch also came alongside partnership agreements with companies in shipping, commercial vehicles and utility-scale storage – part of the company’s stated strategy to build a wider energy-technology ecosystem. Chairwoman Liu Jingyu said CALB aims to achieve operational carbon neutrality by 2030 and full value-chain neutrality by 2040.
As storage suppliers are under pressure to deliver higher-capacity, longer-life and higher-safety platforms, CALB’s 588 Ah and 684 Ah offerings position the company to compete more aggressively in the utility-scale and long-duration segments, where lifetime economics increasingly shape procurement decisions. With mass production expected to start by end of 2025, the industry will closely watch whether the new cells can deliver their promised cost and performance advantages in real-world deployments.