# Thermal behavior and acoustic interrogation analysis of Na-ion commercial batteries

Nicolas Guillet, Olivier Raccurt, Loic Lonardoni, Tessard Romain

► To cite this version:

Nicolas Guillet, Olivier Raccurt, Loic Lonardoni, Tessard Romain. Thermal behavior and acoustic interrogation analysis of Na-ion commercial batteries. Sodium - ion Battery Day, CEA, Jul 2024, Grenoble, France. cea-05445392

HAL Id: cea-05445392

https://cea.hal.science/cea-05445392v1

Submitted on 6 Jan 2026

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# Thermal behavior and acoustic interrogation analysis of Na-ion commercial batteries

Olivier Raccurt, Loïc Lonardoni, Romain Tessard & Nicolas Guillet
# Electrical and physical characterization of commercial Na-ion batteries

**Main characteristics:** Jiangsu Transimage Sodium-ion Battery Technology Co. Ltd.

<figure><img src="image_3.png" /></figure>

**Manufacturer:** JSCY Sodium Tech. Co., Ltd

**Year:** 2023

**Format:** 18650

## Characteristics:

* 1,5 – 4.0 V <3.10 V>

* 1500 mAh (@ C/2, 25 °C)

* 38 g, 122 Wh/kg

* 18 mΩ @ 1 kHz and SoC 50 %

* Std: CC-CV(C/2) – CC(D/2)

* Fast: CC-CV(1C) – CC(3D)

* Temperature: charge -10 – +45°C
  Discharge -30 – +60 °C

<table><tr><td>江苏传艺钠电科技有限公司<br>Jiangsu Transimage Sodium-Ion Battery Technology Co., Ltd.</td><td>编号: CY-WI-RD-051<br>版本: 1.0 校验文件<br>日期: 2023-03-05</td></tr><tr><td colspan="2">18650E-1500mAh 产品规格书</td></tr></table>

Customer/客户:

Sodium-Ion Battery
Specification
钠离子电池规格书

MODEL:18650E

(1500mAh)

<table><tr><td>Prepared By/Date<br>编制/日期</td><td>Checked By/Date<br>审核/日期</td><td>Approved By/Date<br>批准/日期</td></tr><tr><td>江传艺 2023.3.8</td><td>江传艺 2023.3.8</td><td>江传艺 2023.3.8</td></tr></table>

<table><tr><td rowspan="3">Customer<br>Approval</td><td>Signature/Date(签名/日期)</td><td></td></tr><tr><td>Company Name(公司名称)</td><td></td></tr><tr><td>Company Stamp(公司印章)</td><td></td></tr></table>

<figure><img src="image_4.png" /></figure>
# Electrical and physical characterization of commercial Na-ion batteries

## Influence of temperature ?

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

Ouch! It behaves rather badly at low temperatures... Severe irreversible reactions !!

<table><thead><tr><th></th><th>Qcharge</th><th>Qdischarge</th><th>Echarge</th><th>Edischarge</th><th>n faradic</th><th>n energ</th><th>E dissip (Wh)</th></tr></thead><tbody><tr><td>5 °C</td><td>2099</td><td>1279</td><td>7.13</td><td>3.61</td><td>60.94%</td><td>50.66%</td><td>3.516</td></tr><tr><td>25 °C</td><td>1401</td><td>1392</td><td>4.46</td><td>4.11</td><td>99.31%</td><td>92.30%</td><td>0.343</td></tr><tr><td>45 °C</td><td>1407</td><td>1405</td><td>4.38</td><td>4.17</td><td>99.80%</td><td>95.13%</td><td>0.213</td></tr></tbody></table>

<figure><img src="image_8.png" /></figure>

* Large effect of temperature on the central redox peak (phase II)

* Significant influence of temperature on electrical characteristics ($E_{act} \sim 38 \text{ kJ.mol}^{-1}$, close to LFP $\sim 33 \text{ kJ.mol}^{-1}$ T. Richard Jow et al 2012 J. Electrochem. Soc. 159 A604)
# Electrical and physical characterization of commercial Na-ion batteries

## Thermal analysis

### experimental setup

<figure><img src="image_9.png" /></figure>

Heat exchanged by a battery with its surrounding during operation

<figure><img src="image_10.png" /></figure>

thermal flow sensor wrapped around a 18650-type battery

<figure><img src="image_11.png" /></figure>

Example of thermal flow recorded during cycling (2 successive cycles) at 25 °C

### experimental conditions:

- isothermal conditions ($\max(\Delta T_{cell}) < 0.5$ °C)

- Long rest periods between active phases (> 1 h for a 18650-type battery cell)
# Electrical and physical characterization of commercial Na-ion batteries

## Thermal analysis

* experimental results at 25 °C

<figure><img src="image_12.png" /></figure>

<figure><img src="image_13.png" /></figure>

* thermal behavior very different between charging and discharging

* strong endothermic phenomenon during charging (and exothermic during discharging)

* for a same SoC, the system is in very different states if it is charging or discharging !!!!!

<table><thead><tr><th>E charge (Wh)</th><th>Heat charge (Wh)</th><th>η energ. charge (%)</th><th>E discharge (Wh)</th><th>Heat charge (Wh)</th><th>η energ. discharge (%)</th><th>η energ. full cycle (%)</th></tr></thead><tbody><tr><td>4.46</td><td>0.045</td><td>98.98 %</td><td>4.11</td><td>0.298</td><td>93.31 %</td><td>92.30 %</td></tr></tbody></table>

→ High efficiency during charge / large release of heat during discharge
# Electrical and physical characterization of commercial Na - ion batteries

## Thermal analysis

* experimental results at 25 °C

<figure><img src="image_14.png" /></figure>

* thermal behavior highly correlated to electrochemical peaks

* ~athermal behavior during charge, excepted in phase II → endothermal reaction

* significant exothermic behavior during discharge
# Electrical and physical characterization of commercial Na-ion batteries

## Thermal analysis

### experimental results at 5 °C

<figure><img src="image_15.png" /></figure>

<figure><img src="image_16.png" /></figure>

- very high exothermal phenomena noted during charge at 5 °C (→ irreversible loss of capacity)

- similar thermal behavior recorded during discharge at 5 and 25 °C

<table><thead><tr><th>E charge (Wh)</th><th>Heat charge (Wh)</th><th>η energ. charge (%)</th><th>E discharge (Wh)</th><th>Heat charge (Wh)</th><th>η energ. discharge (%)</th><th>η energ. full cycle (%)</th></tr></thead><tbody><tr><td>7.13</td><td>2.90</td><td>59.30 %</td><td>3.61</td><td>0.46</td><td>87.34 %</td><td>50.66 %</td></tr></tbody></table>

→ Strong irreversible reactions observed during charge at low temperature
# Electrical and physical characterization of commercial Na - ion batteries

## Thermal analysis

### experimental results at 5 °C

<figure><img src="image_17.png" /></figure>

* A small exothermic reaction is noted during charge when cell voltage > 3.10 V (second part of Phase II)

* Similar thermal behavior during discharge at 25 °C and 5 °C

→ What happened to the missing electrons on discharge?

<figure><img src="image_18.png" /></figure>
# Electrical and physical characterization of commercial Na-ion batteries

## Acouric interrogation

### ■ principle

<figure><img src="image_19.png" /></figure>

non-destructive test (NDT) method;

- sensitive to the propagation of acoustic waves throughout the battery's materials;

- acoustic waves interact with materials and interfaces

→ Detect materials density variations, discontinuities, defects, bubbles generation...
# Electrical and physical characterization of commercial Na-ion batteries

## Acoustic interrogation

* parameters of interest ?

### Time of Flight
(delay between emission and reception)

<figure><img src="image_20.png" /></figure>

Depending on the distance between the transducers and the sound speed in the materials (related to **density / Young modulus**)

<figure><img src="image_21.png" /></figure>

### Shape of the waveform

<figure><img src="image_22.png" /></figure>

Depending on the interactions of the acoustic wave with the materials / interfaces inside the battery (**porosity / interfaces**)

### Power spectrum density

<figure><img src="image_23.png" /></figure>

Energy and strength of the signal transmitted depending on the properties of the materials (**density, Young modulus, porosity etc...**)

→ Highly sensitive to physical properties evolution of battery materials during cycling / ageing
# Electrical and physical characterization of commercial Na - ion batteries

## Acoustic interrogation

* experimental setup

* 2 commercial PZT piezoelectric transducers placed positioned diametrically opposite on the surface of the cell cylinder

* Emission acoustic signal 20 – 300 kHz, duration 1 ms, amplitude 0.5 V, every 5 min

* Pre-amplifier for recording emission signal (20 dB) and reception signal (60 dB)

<figure><img src="image_24.png" /></figure>

Ø 20mm, thickness 600 µm
~ 0.3 €

https://www.reichelt.com/fr/fr/-l-ment-pi-zo-lectrique-6-4-khz-400-ohms-c-bl-epz-20ms64w-p145915.html

<figure><img src="image_25.png" /></figure>

<figure><img src="image_26.png" /></figure>

Example of signal emitted (black line) and transmitted through the battery cell (red line)
# Electrical and physical characterization of commercial Na - ion batteries

## Acoustic interrogation

* experimental results: charge – discharge cycles 25 °C, 750 mA

<figure><img src="image_27.png" /></figure>

* The energy of the transmitted acoustic signal shows a similar evolution with each cycle.

* However, there is a sudden and irreversible increase in the energy of the acoustic signal at the end of each discharge.

→ something not so great happens at the very end of the discharge, causing each time an irreversible change in the physical properties of the materials in the battery
# Electrical and physical characterization of commercial Na - ion batteries

## Acoustic interrogation

* experimental results: CV 50 µV.s⁻¹, 25 °C

<figure><img src="image_28.png" /></figure>

* Reversible evolutions during cycling: strong evolution between 2.5 and 3.0 V (Phase II)

* The redox peak of phase II spreads out considerably during charging, but is much faster under discharge

* Irreversible evolution during rest period after discharge (1.50 < Ucell < 1.72 V)

→ May be not a very good idea to discharge the battery below 1.75 V

<figure><img src="image_29.png" /></figure>
# Electrical and physical characterization of commercial Na - ion batteries

## Acoustic interrogation

* experimental results: charge – discharge cycles 5 °C, 750 mA

<figure><img src="image_30.png" /></figure>

* Behavior at 5°C very different from that at 25°C when charging (similar behavior when discharging).

* Very large evolution of the absolute energy of the acoustic signal during charge, correlated to heat flow evolution !!!

→ Materials temperature has a major effect on the transportation of acoustic waves
# Electrical and physical characterization of commercial Na - ion batteries

## Conclusions

* Energy density (122 Wh/kg) close to LFP/G batteries **BUT** significant improvements still seem necessary to guarantee performance and durability equivalent to LFP/G

* Thermal analysis and acoustic interrogation techniques have been proposed to complement the electrochemical methods usually used to characterize these systems.

* → Thermal analysis is useful to measure the energy efficiency

* → Quantitative measurement of dissipated energy in reversible and irreversible mechanisms

* → Acoustic interrogation can be used to monitor reversible / irreversible variations in the physical properties of battery materials

* → Irreversible phenomena are revealed (consequence of deep discharge)

* **NEXT:** better understanding of the ageing and other irreversibles phenomena

<figure><img src="image_31.png" /></figure>

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