Topsoe Claims Major LNMO Battery Breakthrough With 1,500 Cycles at 80% Capacity Retention

Topsoe – A significant breakthrough in LNMO battery cycle life

At Topsoe, we have achieved a major breakthrough in next-generation battery technology, demonstrating 1500 charge-discharge cycles with 80% capacity retention in LNMO-graphite battery cells. Cycling data is shown in Figure 1. This represents a 3-5x improvement over conventional LNMO performance and meets the demanding durability requirements for automotive electric vehicle applications.

This milestone removes a critical barrier to the widespread adoption of LNMO (lithium nickel manganese oxide) cathode materials, bringing cobalt-free, high-performance batteries closer to commercial reality.

LNMO cathode materials offer a compelling value proposition for the battery industry:

→Price-Performance ratio: With energy density close to NMC at a cost of LFP

→Low cost: Rich in cheap and abundant manganese, cobalt-free, and full utilization of lithium

→High working potential: Delivering energy density comparable to high-nickel cathodes  

→Environmental benefits: More sustainable sourcing and production

Unfortunately, most LNMO batteries have historically suffered from poor cycle life, typically achieving only 250-500 cycles at 25°C before reaching 80% of initial capacity. This has prevented them from competing with established cathode chemistries in demanding applications like electric vehicles, which typically require 1000-1500 cycles.

The challenge: Why LNMO batteries degrade

The root cause of poor LNMO cycle life lies in the very feature that makes it attractive: its high operating voltage. At 5V, LNMO batteries experience accelerated degradation through several interconnected mechanisms:

Electrolyte breakdown and chemical crosstalk

The high voltage causes conventional electrolytes to degrade at the cathode surface. This triggers a cascade of problems:

→ HF is formed in the electrolyte             

→ Manganese dissolves from the cathode into the electrolyte

→ Dissolved manganese migrates to the anode and damages the SEI layer

→ Continued growth of the SEI layer leads to loss of lithium and capacity fade

This phenomenon, where degradation products from one electrode affect the other, is called chemical crosstalk.

Electrode imbalance and lithium plating

A second challenge comes from a phenomenon known as ‘non-chemical crosstalk’ that relates to electrode balancing and voltage window. When the voltage window and electrode capacity ratios aren’t optimized for LNMO’s unique characteristics, the anode can be pushed into extreme states that will either cause lithium plating, with metallic lithium deposits forming on the anode surface instead of intercalating properly into the graphite, or lead to decomposition of SEI layer. Lithium plating is particularly dangerous because it creates safety risks (dendrites can pierce the separator) and accelerates further degradation.

In LNMO systems, these problems compound each other: Manganese dissolution damages the SEI, which makes lithium plating more likely, which causes more degradation, creating a vicious cycle that limits battery life.

Our solution: A multi-pronged approach

Solving the LNMO cycle life challenge required addressing both material chemistry and cell-level engineering. Our approach tackles the problem from multiple angles:

1. Advanced Material Design

We developed a new generation (Generation 3) of LNMO cathode active material with:

→ Improved oxidation stability: The material better resists high-voltage stress, reducing electrolyte degradation

→ Reduced manganese dissolution: Minimizing the chemical crosstalk that damages the anode

→ Better surface stability: Our Gen3 material shows much less self-discharge compared to Gen2, indicating superior stability

As shown in Table 1, these improvements have significantly increased cycle life at both 25°C and 45°C compared to Generation 2.

2. Optimized Voltage Window

LNMO requires slightly different operating parameters than conventional battery chemistries. Through detailed electrochemical analysis using 3-electrode measurement techniques, we identified the optimal voltage window:

→ Lower cut-off: To keep the anode in a safe operating range even as the battery ages, 4.0V is preferred compared to 3.5V, which is often used

→ Upper cut-off: To prevent the anode from reaching potentials where lithium plating occurs during charging, 4.75V is preferred compared to 4.8V and 4.9V, which is often used

These might seem like small adjustments, but they make a dramatic difference. Cycling data with LNMO Gen2 as cathode material comparing upper cut-off of 4.75 V with 4.80 V is shown in Figure 2. It is seen that cycling is significantly better with upper cut-off of 4.75 V. Postmortem analysis confirms plating in the cell using upper cut-off of 4.80 V and that using 4.75 V completely eliminates lithium plating.

3. Electrolyte Compatibility

Working with industry partners, we validate that our LNMO materials perform reliably with commercially available electrolytes. The data presented in Figures 1 and 2 are based on ordinary carbonate-based electrolytes that, in addition to stable cycling, show no gas evolution at room temperature, a key indicator of electrochemical stability. In parallel we are exploring electrolyte chemistries beyond the conventional chemical space, which show promise for further improving high-temperature performance. Partnering with Guangzhou Tinci Materials Technology Co., Ltd. (TINCI), we demonstrated that their 5V electrolyte significantly enhanced cycle life of LNMO-graphite cells at 45°C, reaching 80% of initial capacity after 900 cycles and 70% of initial capacity after more than 1600 cycles, while also reducing gas generation. This is almost a doubling of cycle life compared to ordinary carbonate-based electrolytes. The cycling data is shown in Figure 3.

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