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The “Technological Archaeology” of Jueneng New Energy: Insights from Disassembling a Ten-Year-Old Battery
time：2026-08-04
In the failure analysis laboratory of new energy sources, a power PN20160715001 numbered battery pack is being slowly dismantled. It was born in 2016 and retired last month after ten years of loading and service, with a cumulative cycle of more than 5,000 times. This is not an ordinary retired battery, but a "living file"-it records the design decision, material selection and technological level of the products of the previous generation of energy gathering new energy. It is also today ten years later, the most honest technical judgment is given.
I. Unpacking: the physical mark of ten years of wind and frost
the disassembly starts with the appearance inspection of the box.
The protective coating on the surface of the box has local pulverization and slight corrosion, but the overall structure is complete without deformation and crack. The aging of the sealing ring is obvious, and the elastic modulus decreases by about 40% compared with the new product, which explains the slight leakage in the later air tightness test. The box scheme of "aluminum profile + powder spraying" has basically passed the test of ten years of marine climate, but the new energy source has been upgraded to double protection of "anodic oxidation + fluorocarbon coating, the weather-resistant life goal is increased to 20 years.
The hanging point and the weld area of the mounting bracket are the key observation objects. X-Ray inspection shows that there is no crack propagation in the weld seam and the penetration consistency is good. However, there are signs of stress corrosion in some areas-this points to the welding of that year.The post-stress removal annealing process is imperfect. Nowadays, the welding production line of new energy sources has been standard with online annealing process, and residual stress nondestructive testing is introduced.
2. Module disassembly: Cell "aging portrait"
opening the Box, the scene inside the module reveals the microscopic history of ten years of operation.
Cell the overall appearance is good, no drum bag, no leakage, but slight electrolyte crystallization appears on the surface of the positive and negative pole column. This is the trace of water vapor infiltration after the aging of the sealing ring. Although it does not affect the electrical performance, it reminds the importance of long-term sealing reliability. The current sealing design of the new energy source has upgraded fluoro rubber seal ring to Hydrogenated Nitrile Rubber and added a secondary sealing lip structure.
The capacity test shows that the capacity retention rate of the whole package is 78% of the initial value, which is close to the end of the design life. However, the disassembled monomer cell test revealed an interesting phenomenon: the cell capacity retention rate at the edge of the module is 75% on average, while that at the center is 81%. The 3% difference points to the "edge effect" of the thermal management design in that year-the heat dissipation condition of the center cell is better than that of the edge, and the aging rate is differentiated after long-term operation. This discovery directly promoted the development of the current "bionic flow channel" liquid cooling design of the new energy gathering energy, with the goal of compressing the whole package temperature difference from 8℃ of that year to within 3℃.
Internal resistance growth is anotherKey indicators. Ten years later, the DC internal resistance increased by about 45% compared with new products, of which cell contributed 35% to the body and 10% to the corrosion and contact loosening of connectors. The copper-aluminum heterogeneous metal connection used simple mechanical crimping at that time, and long-term electrochemical corrosion led to the increase of contact resistance. Nowadays, the new energy source adopts ultrasonic welding + nickel plating transition scheme to fundamentally eliminate the corrosion path.
3. BMS backtracking: the "time capsule" in the data"
the historical data in the BMS memory is the most precious "time capsule" in this battery pack ".
The charge-discharge cycle curve shows that the first three years are running at a relatively mild 1C rate, and the attenuation is gentle; The fourth year is caused by the adjustment of operation strategy, frequent participation in 2C fast charge, and the attenuation slope is obviously steeper. This data provides empirical support for the current BMS strategy of energy gathering new energy sources-"elastic SOC window" and "segmented fast charge" algorithms, just to achieve a balance between high-income scenarios and long service life goals.
In fault Notitia, 23 Level 3 faults (recoverable protection actions) and 0 level 2 faults (manual intervention required) were recorded. The third-level faults are mainly concentrated in the summer high temperature period, and the triggering reason is the temperature exceeding the limit caused by insufficient heat dissipation capacity. This explains why the design margin of the current thermal management system of the new energy source has been upgraded from "meeting the standard" to "exceeding the extreme working conditions by 20%".
IV. Material aging: Ten-year changes in the micro world
the electrode material under scanning electron microscope (SEM) tells a deeper story.
On the surface of lithium iron phosphate particles, SEI film thickness increases from the initial number of nanometers to about 50 nanometers, which is the cumulative effect of continuous decomposition of electrolyte. Microcracks appear on the edge of some particles, pointing to mechanical stress fatigue in long-term cycle. The interlayer structure of negative graphite remains good, but Lithium Deposition traces are detected in local areas-this is evidence that lithium ions are not completely embedded in graphite and precipitated on the surface during low-temperature fast charging.
Gas chromatographic analysis of electrolyte shows that the content of main solvent components (vinyl carbonate and dimethyl carbonate) decreases by about 15%, and by-products (such as lithium carbonate and lithium fluoride) accumulate. Additives (such as VC and FEC) have been consumed a lot in the early cycle, and the lack of protection in the later stage leads to attenuation acceleration. This discovery has promoted the current development of "wide temperature range electrolyte" for new energy sources, with the goal of maintaining the slow release supply of additives throughout the life cycle.
V. Enlightenment: time is the most stringent reviewer
the dismantling of this ten-year veteran battery has brought three inspirations to the new energy source.
the design margin determines the life ceiling. At that time, the conservative thinking of "meeting the standard" was exposed as a bottleneck on the ten-year scale. The current design philosophy has turned to "exceeding the standard by 20%"-not waste, but awe of the uncertainty of time.
Material selection is a long-term investment. The ordinary sealing ring and simple crimping process used to save costs in that year "recovered" the cost in the way of performance attenuation ten years later. Today's material selection has brought ten-year aging performance into the core evaluation dimension.
Data assets are the fuel for iterative optimization. The billions of operational data accumulated over the battery pack years provide valuable training samples for AI prediction models that gather energy for new energy sources. The SOH prediction accuracy of the current new products largely benefits from the real feedback of these "veterans.
In the laboratory of gathering energy and new energy, dismantle and retire battery it is called "technical archaeology"-not for nostalgia, but for digging the long-term echo of design decisions from the sedimentary layer of time. Every retired battery is a "living teaching material". It will not lie or cater to it. It will only use the capacity attenuation curve, internal resistance growth slope and material micro-morphology to give the most objective technical evaluation.
Contact us
Dongguan Juneng New Energy Technology Co., Ltd.
137 5142 6524（Miss Gao）
susiegao@power-ing.com
Xinghuiyuan High tech Industrial Park, Dalang Town, Dongguan City, Guangdong Province
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