from chemistry to pack
Grid storage cells have grown quickly. The 280Ah and 314Ah LFP prismatic cells that defined the early 2020s are being displaced by 500Ah-plus formats, with 587Ah, 628Ah and 684Ah in production or launch, and claims above 1000Ah announced [1]. The interesting engineering question is where the benefit actually lands. Most of it shows up at … Read more
CATL’s automotive-grade NMC811 prismatic cell ships with a headline safety feature: a “Dual Vent Safety Design.” The specifications: We believe this cell is for ACC. Jerry Wan shared details of this CATL cell on LinkedIn and it got us thinking: Why vent design matters more on NMC811 A cell’s vent only has one job: get … Read more
AION Engineering INC In lithium‑ion battery design, internal resistance is one of the most critical parameters governing power capability, heat generation, fast‑charge performance, and overall efficiency. The difference in internal resistance between wound (spiral/jelly‑roll) cells and Z‑stack (stacked) cells is often misunderstood as a chemistry issue, while in reality it is largely a current‑path and … Read more
Prismatic cells are typically surface-cooled when used in real world scenarios, and we have observed a growing demand for testing methods that align to this. Thus we have been investigating the best methods for replicating the conditions a battery may be used in. Recently, we conducted a surface cooling test on a 314Ah prismatic cell. … Read more
When we talk about Stacked vs Wound cells we are considering the Anode-Separator-Cathode stack and how that is assembled within a battery cell. Kong et al [1] show a simple schematic of the two arrangements. Pouch and Prismatic cells can be stacked or wound, but what is the advantage and disadvantage of each approach? Cell … Read more
The new Xpeng Sepa 2.0 platform debuts on the new G6 EV. We will look at the G6 battery packs in more detail in later posts, but for now it is worth looking at the platform. Especially as this is another cell to body design. SEPA = Smart Electric Platform Architecture When this new platform … Read more
The Polestar 3 shares the Volvo SPA platform with Volvo EX90. Note: Lotus has its own derivative of the SEA platform called EPA. SEA and EPA has many similarities while SPA and SEA is quite different. Metrics This post has been built based on the support and sponsorship from: Thermo Fisher Scientific, Eatron Technologies, About:Energy and Quarto Technical Services. Specifications … Read more
The 2024 Audi Q6 SUV e-tron quattro has a 100kWh battery pack that uses large CATL prismatic cells. A rectangular flat pack design. The first of Audi’s production vehicles based on the Premium Platform Electric (PPE) architecture. The Audi video shows that the pack has a fire protection layer applied over the top of the … Read more
What makes a Blade or Prismatic cell what it is? Blade cells are long, thin and have a terminal at each end. But so do some prismatic cells. Is it the ratio of the side dimensions? The following graph shows data from the Cell Database where we have plotted the ratio between the middle dimension … Read more
How does the choice of cell format influence battery pack mass? The three main cell formats: Cylindrical, Prismatic and Pouch. There are pro’s and con’s with each. One of the most significant differences is the amount of mechanical support required. The pouch cell needs the most support and fixing, followed by the prismatic and the … Read more