CATL’s Lithium Metal Battery Breakthrough Hits 500 Wh/kg with Record Cycle Life

In a landmark study published in Nature Nanotechnology, battery giant CATL has overcome a decades-long hurdle in lithium metal battery (LMB) technology. By pioneering quantitative diagnostic tools, the company identified electrolyte salt depletion—not solvent failure—as the primary cause of LMB degradation, enabling a prototype with unprecedented energy density (>500 Wh/kg) and cycle life (483 cycles).

LMBs promise transformative energy storage for electric aviation and long-range EVs due to their ultra-high energy potential. Yet until now, boosting energy density inevitably shortened battery lifespan. While researchers focused on solvation structures and electrode interfaces, CATL’s team discovered 71% of electrolyte salt (LiFSI) depletes before failure—a critical blind spot in prior research.

"Industry overemphasized Coulombic efficiency while neglecting electrolyte durability," stated Dr. Ouyang Chuying, CATL’s Co-president of R&D. "Salt concentration is fundamental to longevity."

The breakthrough hinged on novel analytical methods that mapped real-time consumption of lithium and electrolytes during operation. This revealed LiFSI loss as the dominant failure pathway, contradicting established theories about dead lithium or solvent breakdown.

CATL’s solution: An optimized electrolyte formula using a low-weight diluent to increase LiFSI concentration without adding mass. The result doubled cycle life while maintaining high efficiency, achieving commercial viability targets.

The research, conducted at CATL’s 21C Lab, signals a paradigm shift in battery design. With 2024 R&D investments hitting $2.59B USD and over 43,000 global patents, CATL continues translating fundamental science into scalable clean energy solutions.

Read the full paper here: https://www.nature.com/articles/s41565-025-01935-y

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