By Kent Griffith
May 12, 2023 | Out with “giga”, in with “tera”. Global lithium-ion battery production capacity stands at roughly 600 GWh per year today and is expected to reach at least 3 TWh by 2030. There is even talk of North American capacity reaching 1 TWh by the end of the decade, up from a paltry 55 GWh at present. A lot of work is required if we are going to transition from billions (“giga”) to trillions (“tera”) of watt-hours of annual battery production. Established manufacturers and new innovators shared their perspectives on the TWh Era at the International Battery Seminar in Florida this spring.
Let’s start with some basics. The vast majority of lithium-ion batteries contain graphite as the anode material and lithium nickel manganese cobalt oxide (NMC) or lithium iron phosphate (LFP) as the cathode. The anode and cathode materials are deposited onto copper and aluminum foil, respectively, by way of water- or solvent-based slurries. The water or solvent is removed through a lengthy, expensive, and energy intensive drying procedure, which is generally considered to be a limiting step in battery manufacturing. The dried coated foils are then stacked or wrapped into cylindrical, pouch, or prismatic cell geometries, also known as form factors. There is a trend toward larger and larger cell sizes to maximize the energy density by increasing the ratio of active materials to casing and to simplify the pack configuration. Geographically, China holds the most established position in battery manufacturing, although the industry is rapidly globalizing to avoid supply chain risks and to minimize the need to ship lithium-ion batteries, which is both dangerous and expensive.
Hailong Ning, from Nio, opened the TWh conversation at the International Battery Seminar with stimulating ideas to move beyond the manufacturing status quo. Nio is a Shanghai-based electric car company but, like many EV companies, they are far more involved in the supply chain than just producing cars. On one hand, Nio is well-known for innovating in the battery swapping space. Battery swapping involves, as the name implies, physically swapping a discharged battery out for a fully charged one at a battery swapping station, which may look something like a modified shipping container. According to Ning, the process can be completed in as little as 3 minutes. Though not immediately obvious, battery swapping has implications for battery manufacturing as it changes the considerations for EV battery size and performance metrics as well as the charging infrastructure. With ‘battery-as-a-service’, Nio owns the batteries, which could be extremely helpful when it comes to end-of-life reuse and recycling. Battery swapping is relatively uncommon in the US and Europe, but Nio has performed millions of swaps in China. They are also adding another 1,000 swap stations in 2023. Ning commented that you can even select a different battery depending on your use case at the time of swap. In a move that is increasingly common for automakers, Nio is also planning to open a cell factory. Among the considerations for cell manufacturing, he noted that the cylindrical format has a distinct advantage in throughput. While pouch and prismatic both have a production rate that has plateaued around 50 pieces per minute, Ning stated that the cylindrical rate is approximately 100 cells per minute and could reach as high as 600 with improved production design. High-speed cell manufacturing is obviously highly automated and requires commensurate quality control measures. To that effect, Nio has developed more than 300 patterns for detecting battery issues.
Rivian, the electric truck and SUV manufacturer, was represented in Florida by Shubro Biswas. Although Rivian does not currently produce their own cells, it is clear that they have thought about it extensively. Biswas, and others, noted that battery gigafactories cost between $80–120 million per GWh per year capacity. The current state-of-the-art is slot die coating followed by drying, but the platonic ideal he outlined is simply coating with no drying. Dry manufacturing is a common theme in discussions of advanced battery manufacturing, which should come as little surprise in the context of the high energy, space, and time requirements required for electrode drying. Dry coating is not one technology; rather there are a variety of strategies such as powder compression, vapor deposition, powder spray, and binder fibrillation. Biswas stated that binder fibrillation has the highest technology readiness level (TRL 7) and one can buy factory-scale equipment. Another route toward advanced manufacturing for the TWh Era may be new drying routes. Biswas described a variety of emerging technologies including infrared drying, laser drying, and microwave drying. His goal, as stated, was to point out that dry electrode manufacturing is a big step, and may be the ultimate goal, but it is not the only development path.
EVs are not the only driver of the TWh Era. Sam Jaffe, E Source, shared insights on the coming wave of energy storage installations on the electricity grid. For this year, the impacts will be felt primarily in Texas and California, but the wave will fan out across the country by mid-decade to support growing intermittent renewable generation. E Source forecasts 3.07 TWh annual battery capacity in 2030 with more than 250 GWh of that going toward stationary storage. Both the total production and the stationary storage projections for 2030 include about half coming from Asia Pacific and half coming from North America and Europe combined.
Jaffe believes battery adoption on the grid will be slower than EV adoption because the power industry operates on a 30-to-50-year cycle while the car industry is on a 10-year cycle. Given the long timelines for infrastructure replacement on the grid, the stationary energy storage installations will rise quickly but likely plateau by the end of the decade and then gradually rise toward 2050. Think of it like an S curve. E Source is predicting 1.15 TWh cumulative battery capacity on the grid by the end of the decade, corresponding to nearly 0.5 TW. The vast majority of this is expected to be “front of the meter” on the utility side. Jaffe notes that “behind the meter” batteries for residential or commercial applications are rarely going to be profitable in the coming decade, but provide high value to customers who require backup power when the grid is down.
The age of terawatt-hour energy storage is upon us. At that scale, small improvements can lead to enormous returns in time, cost, and sustainability of the battery industry. The TWh is being driven primarily by electric vehicles but stationary storage will be a significant contributor. Supply chains are increasingly vertically integrated to ensure that raw material or cell limitations will not impact product deliveries down the line. Although gigafactories are already big business, we can expect to see changes with innovations in electrode and cell manufacturing technology.