The compact structure design of lithium battery packs is the core means to enhance the performance of battery systems and reduce costs. Its advantages are reflected in five dimensions: energy density, heat dissipation efficiency, mechanical reliability, manufacturing cost and system integration. The following is the specific advantage analysis and implementation path:

First, increase the volumetric energy density

Reduce the proportion of ineffective space

The volume utilization rate of traditional battery packs is only 60% to 70% due to structural redundancy (such as connectors, heat dissipation channels, and fixed brackets). Compact design can increase this proportion to 85% to 90%.

Case: By compressing the gap between battery cells from 5mm to 2mm and combining it with three-dimensional stacking arrangement, the volumetric energy density can be increased by 20% to 30%.

Optimize the density of battery cell arrangement

By adopting modular mixed arrangements (such as 4 parallel ×8 series) and irregular-shaped cells (such as trapezoidal or L-shaped), the edges of the installation space can be filled, further enhancing the space utilization rate.

Case: The volume energy density of a certain drone battery pack has been increased from 220Wh/L to 320Wh/L through customized L-shaped cells and vacuum adsorption fixation technology.

Second, enhance heat dissipation efficiency

Shorten the heat conduction path

The compact design, through technologies such as direct cooling with liquid cooling plates and filling with phase change materials (PCM), has shortened the contact distance between the battery cell and the heat dissipation medium from over 10mm in traditional solutions to within 1mm, increasing the heat dissipation efficiency by more than 50%.

Case: A certain electric vehicle battery pack adopts a liquid cooling plate directly attached to the side of the battery cell, combined with a nano aerogel insulation layer, to control the temperature difference of the battery cell within ≤3℃.

Optimize the layout of the heat dissipation channels

Optimize the heat dissipation channels (such as spiral and hexagonal channels) through CFD simulation to reduce dead corners in the channels and improve the utilization rate of coolant.

Case: A certain energy storage battery pack adopts a spiral liquid-cooling channel, which improves the heat dissipation efficiency by 30% compared with the traditional rectangular channel, and reduces the coolant consumption by 20%.

Third, enhance mechanical reliability

Disperse mechanical stress

Compact design reduces the stress peak under vibration conditions by 30% to 40% through interlaced arrangement (such as "Z" shape, spiral shape) and flexible connectors (such as FPC, aluminum wire bonding), thereby extending the battery pack's lifespan.

Case: Under a vibration acceleration of 10g, the battery pack of a certain electric vehicle, through interlaced arrangement and buffer layer design, the maximum stress difference between the cells is ≤15% of the average stress.

Enhance the ability to withstand shocks

By adopting composite material shells (such as carbon fiber reinforced plastic, CFRP) and honeycomb sandwich structures, the weight of the shell is reduced by 40%, while the bending stiffness is increased by 20%, enhancing the impact resistance of the battery pack.

Case: The battery pack of a certain unmanned aerial vehicle (UAV) passed the 3-meter drop test with a CFRP shell and honeycomb aluminum core material. There was no structural damage, and the voltage fluctuation of the battery cells was ≤0.1V.

Fourth, reduce manufacturing costs

Reduce the usage of connecting parts and structural components

Compact design replaces bolt connections with laser welding and wiring harnesses with FPC, reducing the number of connecting parts by more than 30% and lowering the cost of manual assembly at the same time.

Case: A certain energy storage battery pack has achieved a 40% reduction in the cost of connecting parts and a 50% increase in assembly efficiency through laser welding and FPC integration technology.

Simplify the manufacturing process

Adopting integrated molding technologies (such as injection molding and 3D printing) can reduce the number of parts and lower the cost of mold development.

Case: A portable energy storage device used 3D printing technology to produce battery pack brackets, reducing the number of parts from 20 to 5 and lowering the mold cost by 60%.

Fifth, optimize system integration

Adapt to complex installation environments

Compact design, through irregular-shaped battery cells and modular arrangement, can adapt to irregular installation Spaces (such as car chassis grooves and robot joints), enhancing the flexibility of system integration.

Case: The battery pack of a certain automotive Chassis adopts the CTC (Cell to Chassis) technology, directly integrating the battery cells into the chassis frame. The volumetric energy density is increased to 380Wh/L, and the space utilization rate reaches 85%.

Reduce the additional system volume

Through integrated design (such as directly embedding BMS and DC/DC converters into the battery pack end plates), the space requirements for the external electrical compartment are reduced.

Case: A certain unmanned aerial vehicle battery pack was packaged at the BMS chip level (SiP technology), reducing the volume of the BMS to 1/5 of the traditional solution and lowering the overall weight by 20%.

Sixth, advantages of typical application scenarios

Electric vehicle

Compact design can increase the driving range (for example, a 20% increase in volumetric energy density corresponds to a 15% to 20% increase in driving range), while reducing the vehicle weight and improving energy efficiency.

Case: Through three-dimensional stacking and liquid-cooled direct cooling technology, the volume energy density of a certain electric vehicle battery pack has been increased from 280Wh/L to 380Wh/L, and the driving range has been extended by 18%.

drone

Compact design can reduce the volume and weight of the battery pack, and increase flight time and load capacity.

Case: The battery pack of a certain unmanned aerial vehicle (UAV) has increased its volume energy density to 320Wh/L and extended its endurance by 40% through the three-dimensional folding arrangement of soft-pack cells and air cooling for heat dissipation.

Energy storage system

Compact design can increase the energy storage capacity per unit volume, reduce the occupied area and construction cost.

Case: A certain energy storage battery pack has increased its volumetric energy density by 25% through modular hybrid arrangement and aerogel insulation technology, and has passed the UL9540A thermal runaway test.