What Are the Development Trends of Batteries?

Ternary lithium batteries, also known as "ternary polymer lithium batteries," are lithium batteries that use ternary cathode materials such as lithium nickel cobalt manganese oxide (NCM) or lithium nickel cobalt aluminum oxide (NCA). Cobalt, primarily used to stabilize the layered structure of the material and improve cycle and rate performance, is an indispensable precious metal in ternary batteries.

Cost has always been a stumbling block to the development of the new energy vehicle market. As the core cost component, the "power battery" has always been a focus of hope for cost reduction. Reducing the proportion and content of cobalt in ternary lithium batteries will correspondingly lower the overall vehicle cost, weakening the impact of cobalt price fluctuations on companies. This will allow companies to shift from a proactive to a reactive approach, which will benefit the development of the new energy vehicle market.

Solid-state batteries are a type of battery technology. Unlike the commonly used lithium-ion and lithium-ion polymer batteries, solid-state batteries use solid electrodes and solid electrolytes.

Because the scientific community believes that lithium-ion batteries have reached their limits, solid-state batteries have recently been seen as a potential successor to lithium-ion batteries. Solid-state lithium battery technology uses a glass compound made of lithium and sodium as the conductive material, replacing the electrolyte of traditional lithium batteries, significantly improving the energy density of lithium batteries.

Solid-state electrolytes have a high electrochemical stability window, allowing them to be used with high-voltage electrode materials to further increase battery energy density. Solid-state electrolytes also possess high mechanical strength, effectively suppressing lithium dendrite penetration during battery cycling, making it possible to use metallic lithium, which has a high theoretical energy density, as the negative electrode material. A drawback of solid-state electrolytes (a current development challenge) is the extremely high solid-solid contact resistance between the electrode and the electrolyte.

The blade battery is a completely new design concept that uses long cells while eliminating the intermediate module stage, directly integrating the cells into the battery system. This effectively reduces weight and cost, similar to CATL's CTP (Cell-to-Pack) technology. Meanwhile, BYD's battery structure design borrows the principle of honeycomb aluminum plates, using structural adhesive to fix the battery cell between two layers of aluminum plates, allowing the cell itself to act as a structural component to increase the overall system strength.

(Traditional square batteries VS Blade batteries)

Company C's product is 148 mm long, 79 mm thick, and 97 mm high, with an internal coiled structure, resembling a brick. The blade battery cell is 960 mm long, 13.5 mm thick, and 90 mm high, with an internal stacked structure. Its long, thin shape resembles a blade, hence the name "blade battery."

The stacking process involves cutting the positive and negative electrodes into small pieces, stacking them with a separator to form small battery cells, and then stacking and connecting these small cells in parallel to form a large battery cell. This is a Li-ion battery cell manufacturing process.

For example, pouch lithium batteries rely on "stacking," such as a "Z"-shaped stacking. First, the positive and negative electrode materials are cut into rectangular sheets of the same size, then stacked onto a separator. The separator runs in a "Z" shape between the electrodes, separating them, and finally, it's wrapped in aluminum-plastic packaging.

ACEY-SSM-C Battery Stacking Machine is a device that can be applied to the stacking process of lithium-ion battery pole pieces. The process of manual film loading, subsequent pole piece position correction and lamination is completed automatically, which has the characteristics of high lamination efficiency and high accuracy.

The stacking process is complex, mainly due to the cutting of the electrode sheets and separator. However, the electrode sheet cutting yield is low, and it's difficult to maintain high consistency in quality (cross-section, burrs, etc.), and the alignment accuracy is insufficient. This places high demands on the manufacturing process quality. This is the main reason why stacked batteries haven't become widespread.

CTP technology, short for Cell To Pack, eliminates the module design, directly integrating the cells into a battery pack, which is then integrated into the vehicle's floor as part of the overall structural components.

This approach reduces the amount of material used in the module itself, such as side plates, end plates (module structural components), and beams (battery pack support structures) that were originally used to separate and connect modules. This greatly simplifies the overall battery structure, frees up space, allows for increased battery pack capacity of the same size, and reduces battery pack weight, thereby increasing battery energy density and reducing cost.

CTP technology currently has two different approaches. There are two main approaches: First, the complete elimination of modules, exemplified by BYD's Blade Battery; and second, the integration of small modules into large modules, represented by CATL's CTP technology.

BYD Blade Battery vs. CATL CTP

CTC technology, short for Cell to Chassis, was described by Zeng Yuqun, Chairman of CATL, at the China Automotive Blue Book Forum as follows: "This technology integrates the battery cell and chassis together, and further integrates the motor, electronic control system, and vehicle high-voltage components such as DC/DC converters and OBCs through an innovative architecture. It also optimizes power distribution and reduces energy consumption through an intelligent power domain controller. CTC will enable new energy vehicles to directly compete with gasoline vehicles in terms of cost, provide more passenger space, and improve chassis passability."

In a sense, CTC can be understood as a further extension of CTP. Its core lies in eliminating the module and packaging process, directly integrating the battery cell onto the vehicle chassis, achieving a higher degree of integration.

Traditional Technology vs. CTP vs. CTC

The emergence of CTC breaks through the limitations of PACK (pack technology) and directly involves the vehicle chassis, the most critical core component of the entire vehicle. It represents a core advantage accumulated by OEMs through long-term development and is something battery companies/specialized PACK companies find difficult to develop independently. Therefore, some battery suppliers are now planning chassis development.

At the Giga Fest event held at its Berlin factory last year, Tesla showcased its 4680 Structural Battery (CTC) solution-the 4680 battery pack eliminates the module design, with cells densely arranged in the vehicle chassis. The battery cover serves the dual functions of sealing the battery and the vehicle floor, and seats can be directly mounted on the battery pack.

From cobalt-free and solid-state batteries to blade batteries, stacking processes, and now integrated technologies like CTP/CTC, current battery technology development presents a clear main theme: pursuing ultimate energy density, lower cost, and higher integration efficiency while ensuring safety.

These technologies do not exist in isolation but are intertwined and evolving together. For example, cobalt-free technology aims to solve the bottleneck problem of raw material costs; solid-state batteries are seen as the next-generation solution to break through the bottlenecks of energy density and safety; blade batteries and stacking processes innovate from the perspective of cell structure and manufacturing; CTP/CTC technology redefines the relationship between batteries and vehicles from the perspective of system integration, and is a revolutionary step to improve pack efficiency and optimize vehicle design.

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