What Factors Will Affect The Safety And Reliability Of Lithium Batteries

- Apr 24, 2020-

What Factors Will Affect the Safety and Reliability of Lithium Batteries?


China's production capacity for lithium-ion batteries is rapidly increasing, but under scale expansion, the importance of its safety and quality must be ensured, especially in the event of multiple battery fires and the Korean market stalling. The Clean Energy Association (CEA) released the 2019 BESS Supplier Market Intelligence Program Report, which covers 40 suppliers and aims to help buyers understand the supplier field. The following will tell you which factors will affect the safety and reliability of lithium ion.


Since 2010, the price of lithium batteries has fallen by about 85%. According to CEA analysis, by 2030, the global annual demand for lithium-ion batteries is expected to exceed 2000 GWh. Although most of the demand is expected to be used for electric vehicles, 5% -10% will be used for fixed battery energy storage systems (BESS). Although in the higher level of renewable energy penetration, other energy storage technologies that are more suitable for long-term use and low cost will be introduced, for now, lithium ion seems to be the leading technology because it is brought by the electric vehicle industry. With the benefits of large scale, low cost and standardization can be achieved.


At the same time, people are refocusing on quality and safety, no longer relying on guarantees backed by balance sheets, and no longer relying on very few suppliers. From upstream factory battery quality control to more comprehensive due diligence such as system design and fire protection, it is becoming a principle issue for battery companies and regulatory agencies. There are many variations of lithium ion electrochemistry (LMO, LTO, LCO, NCA, NCM and LFP), but currently only nickel cobalt manganese (NCM), nickel cobalt aluminum (NCA, only used by Panasonic and Tesla) and lithium iron phosphate (LFP) has realized a large-scale energy storage system.


The type of battery has a certain relationship with the area. For Korean suppliers, nickel cobalt manganese (NCM) is the main choice for BESS. By the end of 2019, the annual production capacity of nickel cobalt manganese is expected to be 54 GWh. In North America, Tesla ’s Gigafactory 1 has an annual capacity of Panasonic NCA 21700 cylindrical battery 34 GWh. The batteries produced are mainly used in Tesla ’s electric vehicle products.


Chinese suppliers have strong manufacturing capabilities for nickel-cobalt-manganese (NCM) and lithium iron phosphate batteries (LFP), even including some nickel-cobalt-aluminum (NCA), and the production line can be switched between chemical reagents relatively easily. The chemical properties of LFP determine its safety and reduce the risk of thermal runaway. However, since energy density is the most important factor in expanding the application of electric vehicles, China has already seen a shift to higher energy density nickel-cobalt-manganese (NCM) batteries. Even so, due to the limitation of safety factors, in some transportation fields, LFP batteries are mandatory to install.


At present, LFP is still one of the important choices of Chinese BESS suppliers. Some companies provide LFP batteries with a longer life cycle than NCM batteries. More importantly, LFP batteries do not contain cobalt and have an inherently more stable cost roadmap. The main reason for the instability of the cobalt supply chain is that 60% of the global supply comes from the Democratic Republic of Congo. This is also a key factor in the recent price increase of nickel-cobalt-manganese (NCM) batteries, and Chinese suppliers are very reluctant to large-scale BESS provides nickel-cobalt-manganese (NCM) because it increases the risk of thermal runaway in large systems.


For LFP, its disadvantage is lower energy density, but its advantage is that it has more stable, lower-cost raw material prices, higher cycle life and lower risk of thermal runaway, which makes it in energy storage. Occupy a seat. It is foreseeable that China will strictly enforce lithium iron phosphate battery LFP, while South Korea will strictly enforce nickel-cobalt-manganese (NCM) lithium battery. In addition, lithium titanate batteries that are not widely used are considered as "substitutes" because they are only suitable for some special applications such as high charge and discharge rates and high cycles. Many people in the industry believe that lithium titanate is very It is suitable for military industry and other fields that have extremely high requirements on battery stability.


Earlier this year, South Korea reported 23 fire accidents in energy storage power stations, which was just after the upsurge of large-scale energy storage installations. The Ministry of Trade, Industry and Energy (MOTIE) randomly restricted newly installed equipment and severely restricted the operating conditions of existing equipment. Subsequently, MOTIE conducted a six-month investigation, which was announced in June this year. The investigation found that the possible causes of the fire include insufficient protection, insufficient supervision of environmental conditions, installation defects and inadequate integration. In addition, MOTIE also puts forward additional requirements for the manufacturing quality, installation, operation and maintenance of batteries and personal computers, as well as fire protection.


Investors are highly concerned about the Korean energy storage power plant incident, because the Korean BESS supply chain is considered to be one of the most technologically advanced supply chains in the world. After experiencing this series of events, investors realized that energy storage may still be a relatively new industry, so it is necessary to conduct independent supervision at each stage of production and integration. CEA audit data reveals a more complex reality: At the battery level, defective coatings and folded electrodes may pose a fire risk and reduce battery life. Battery, module, and rack-level protection must be in place and ensure full functionality during testing, otherwise there will be a security risk.


The factory acceptance test of the BESS system must be carried out independently, and the details including performance and safety must be very detailed. The system design and warranty structure must be analyzed and evaluated by a third party to protect buyers from the risks of safety or poor performance and help them understand the cost structure of the product. By 2019, the total installed capacity of the four largest suppliers in China will reach 135 GWh, and the total installed capacity of the four largest international suppliers will reach 119 GWh. By 2021, the total installed capacity is expected to be 230GWh and 250GWh, respectively. China's small battery suppliers will reach 140 GWh in 2019 and 227 GWh in 2021. Thanks to CATL and BYD's rapid growth in electric vehicles, Chinese manufacturers have been able to rank among the world's four giants, Panasonic, LG Chem, Samsung SDI and SKI.


Although there are some doubts that Chinese suppliers may not be as good as those four battery manufacturers mentioned above, China can find the importance of BESS in the proportion of BESS's R & D expenditure in lithium battery revenue. In the next 6 years, the number of BESS installations is expected to increase 10 times. Therefore, buyers must diversify the supply chain, learn how to understand the complexity of the supply chain, and achieve the correct combination of due diligence and supervision.