Stationary batteries from the specialist
HiTHIUM’s production, in contrast to the other large-scale suppliers of lithium-ion batteries, is concentrated exclusively on the area of stationary battery storage. HiTHIUM has taken an unusual path with this specialisation. But the company’s focus serves its customers because HiTHIUM products are relentlessly optimised for stationary use, setting new standards for cost-effectiveness, reliability, and safety.
Quality
The longevity, safety, and economy of Hithium products rely in large part on the characteristics and manufacturing quality of HiTHIUM LFP battery cells. Deviations in production can affect not only the performance or durability of the cells, but, more importantly, their safety. Even the smallest impurities or irregularities can damage cells during operation and thus trigger further defects.
Mass production of battery cells is extremely demanding, given the highly complex manufacturing technologies and minimal manufacturing tolerances.
But Hithium not only relies on the extensive hands-on experience of its core production team’s many engineers in the industrial mass production of battery cells, it has invested heavily in its battery cell manufacturing to build one of the most advanced production lines in the world.
That’s why a large number of the more than 1,000 engineers and researchers who work across the company's four in-house research facilities are dedicated to solving production issues, as well as continually advancing manufacturing processes.
HiTHIUM’s production lines, moreover, have an extremely high degree of automation and a high level of „intelligence“ based on the precise and extensive collection and evaluation
of big data, in real time.
HiTHIUM’s production lines have more than 3000 process control points monitored in real time, of which more than 600 control points are directly associated with an certified quality management system.
In this way, product stability and consistency can be guaranteed in multiple dimensions.
HiTHIUM’s intelligent MES (Manufacturing Execution System) also has more than 600 process control points, as well as a wide variety of data collection channels (RFID, PLC, IPC, PC, etc.) covering the entire factory production site.
Safety
Lithium battery storage systems that are produced, planned, and installed according to current standards are very safe. And yet there are differences that are relevant to safety, e.g. between the various cell chemistries, technologies, designs, storage concepts, and battery management systems (BMS).
Cell chemistry
It is well-known that lithium-ion batteries can burn if damaged or heated to extreme temperatures. The cause is the sensitivity to excess temperatures of the lithium-mixed oxides used in the cell. There are lithium oxides for which so-called thermal runaway occurs at temperatures as low as ca. 180 degrees Celsius.
Of the most commonly used lithium oxides, lithium iron phosphate is the most temperature-resistant, however, only becoming sensitive at approximately 220 degrees Celsius. In this comparison, LFP cells thus have the greatest thermal safety reserves.
HiTHIUM has increased this intrinsic safety of LFP battery technology even further and developed its own proprietary LFP. By means of a so-called lattice doping, the HiTHIUM team has achieved both a higher capacity and a lowered internal resistance of the cell.
Special cell technologies
A number of other innovative technologies developed exclusively by HiTHIUM are also used in the cells. For example, the new current collector developed by HiTHIUM is treated using a thin-film process, thereby further enhancing the intrinsic safety of the battery. The special surface coating leads to less expansion of the material during operation as well as to improved material conductivity and reduced internal resistance of the cell
General safety features of HiTHIUM LFP cells
The general safety devices of the cells ensure that in the event of exceptional operating conditions, a structural device or material property counteracts the malfunction and the cell is brought into a safe state.
| OSD | (Overcharge Safety Device) interrupts the power supply in case of overcharge, or short-circuits the charging current externally. |
| Vent | (safety valve) If the internal pressure of the cell is too high, the excess pressure can escape by means of a predetermined breaking point. |
System safety of HiTHIUM battery storage systems
Although the safety of battery storage systems is based firstly on the properties of the cells used, an enormous role is played in increasing the safety of HiTHIUM battery storage systems by the three-stage BMS, as well as other protective devices, such as thermal management and active fire protection technologies.
- Liquid cooling ensures a controlled operating temperature even at maximum load.
- A highly-developed Battery Management System (BMS) ensures the optimal operational management and monitoring of each individual battery cell. By balancing the states of charge of the individual cells during operation, the BMS prevents the heating of cells with deviating voltage levels. This not only secures more efficient charging and discharging, but also an optimal operating state of the cells, regardless of the load.
- The optimised fire protection strategy consists of multi-level prevention as well as comprehensive monitoring of system safety. In containers, this includes smoke detectors and an active fire extinguishing system.
Safety and reliability tests
HiTHIUM's safety tests cover the testing requirements, from the cell to the battery system. In total, over 24 different safety and reliability tests are performed, such as thermal runaway, nail and drop tests.
Nail Penetration Test
Test conditions:
- Steel needle, diameter = 8 mm
- Speed: 25 mm/s
- Pokes in, stays in the cell and rests for 1 hour.
The cell must not catch fire.
Crush Test
Test condition:
- Half cylinder, radius = 75 mm
- Speed: 5 mm/s
- Deformation ≥ 30 % or U = 0 V
- Or pressure ≥ 13 kN
After the crushing process, the cell rests for 1 hour. The cell must not catch fire.
Economy, performance & durability
HiTHIUM's massive investment in research and development enables not just safety advances, but also improves the technical characteristics and performance as well as the cost-effectiveness of its products. HiTHIUM maintains a strong focus on reducing the LCOE (Levelised Cost of Energy), primarily by increasing the cyclic lifetime and significantly slowing down degradation.
Thanks in part to the modification of the anode with a technology for the active and sustained release of lithium ions, HiTHIUM LFP 300 Ah battery cells, unlike normal LFP cells, still retain their rated capacity after the first 1,000 cycles. They are subsequently able to maintain this advantage, in terms of slowed degradation, over their entire lifetime.
Thus, batteries with HiTHIUM LFP 300 Ah cells can realise an 18% higher energy throughput during their lifetime, compared to commercially available LFP cells.
