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JP-7854627-B2 - battery

JP7854627B2JP 7854627 B2JP7854627 B2JP 7854627B2JP-7854627-B2

Inventors

  • 大戸 貴司
  • 藤本 正久

Assignees

  • パナソニックＩＰマネジメント株式会社

Dates

Publication Date
20260507
Application Date
20221125
Priority Date
20211207

Claims (16)

  1. Positive electrode and, The negative electrode and, An electrolyte layer located between the positive electrode and the negative electrode, Equipped with, The positive electrode has a positive electrode active material layer, The positive electrode active material layer contains a compound having a transition metal element and an oxoanion, and capable of intercalating and releasing lithium ions. The negative electrode comprises a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer contains BiNi, The BiNi mentioned above has a monoclinic crystal structure whose space group belongs to C2/m. battery.
  2. The oxoanion comprises B, Si, P, or S. The battery according to claim 1.
  3. The oxoanion is BO33- , SiO44- , PO43- , P2O74- , or SO42- . The battery according to claim 2.
  4. The electrochemical reaction between the aforementioned compound and lithium includes a two-phase coexistence reaction. The battery according to claim 1 .
  5. The aforementioned compound has an olivine structure, The battery according to claim 1 .
  6. The transition metal element is at least one selected from the group consisting of Fe, Mn, Co, and Ni. The battery according to claim 1 .
  7. The positive electrode active material layer contains LiFePO4 , The battery according to claim 1 .
  8. The negative electrode active material layer includes at least one selected from the group consisting of LiBi and Li3Bi . The battery according to claim 1 .
  9. The negative electrode active material layer does not contain a solid electrolyte. The battery according to claim 1 .
  10. In the X-ray diffraction pattern of the negative electrode active material layer obtained by surface X-ray diffraction measurement using Cu-Kα rays, Let I(1) be the height intensity of the maximum peak that exists in the diffraction angle range 2θ from 29° to 31°. When I(2) is the height intensity of the maximum peak that exists in the diffraction angle range 2θ of 41° to 43°, The ratio of I(2) to I(1), I(2)/I(1), is 0.28 or less. The battery according to claim 1 .
  11. The battery according to claim 1 , wherein the negative electrode current collector includes at least one selected from the group consisting of Cu and Ni.
  12. The negative electrode active material layer is a heat-treated plating layer. The battery according to claim 1 .
  13. The electrolyte layer is a solid electrolyte layer. The battery according to claim 1 .
  14. The solid electrolyte layer comprises a halogenated solid electrolyte. The aforementioned halogenated solid electrolyte is sulfur-free. The battery according to claim 13 .
  15. The solid electrolyte layer contains a sulfide solid electrolyte. The battery according to claim 13 .
  16. The electrolyte layer contains an electrolyte solution. The battery according to claim 1 .

Description

This disclosure relates to batteries. In recent years, lithium-ion secondary batteries, which have seen extensive research and development, are heavily influenced by the electrodes used. Battery characteristics such as gravimetric energy density, volumetric energy density, charge/discharge voltage, charge/discharge cycle life, and storage characteristics are significantly affected by these factors. Therefore, improving the electrode active material is a key strategy for enhancing battery characteristics. For example, lithium-ion secondary batteries that use aluminum, silicon, tin, etc., which are electrochemically alloyed with lithium during charging, as electrodes have been proposed for a long time. Patent Document 1 discloses a lithium-ion secondary battery comprising a negative electrode, a positive electrode, and an electrolyte, the negative electrode material being made of an alloy having silicon, tin, and a transition metal. Patent Document 2 discloses a lithium secondary battery comprising a negative electrode, a positive electrode, and an electrolyte, the negative electrode being a silicon thin film provided on a current collector as an active material. Bismuth (Bi) is an example of a metal that alloys with lithium. Non-patent document 1 discloses a negative electrode containing Bi as the negative electrode active material, which is made using Bi powder. Patent No. 4898737Patent No. 3733065 Hiroyuki Yamaguchi, "Synthesis of Amorphous Polymer Anode Active Materials for Lithium Batteries Composed of Reaction Products of Polyacrylic Acid and Metal Oxides and Their Electrochemical Properties," Doctoral Dissertation, Mie University, 2015.A. K. Padhi, K. S. Nanjundaswamy, and J. B. Goodenough, “Phospho-olivines as Positive-Electrode Materials for Rechargeable Lithium Batteries”, J. Electrochem. Soc., 144, 1188 (1997).Shou-Hang Bo, Kyung-Wan Nam, Olaf J. Borkiewicz, Yan-Yan Hu, Xiao-Qing Yang, Peter J. Chupas, Karena W. Chapman, Lijun Wu, Lihua Zhang, Feng Wang, Clare P. Grey, and Peter G. Khalifah, “Structures of Delithiated and Degraded LiFeBO3, and Their Distinct Changes upon Electrochemical Cycling”, Inorg. Chem. 53, 13, 6585-6595(2014)Laura Lander, Marine Reynaud, Javier Carrasco, Nebil A Katcho, Christophe Bellin, Alain Polian, Benoit Baptiste, Gwenaelle Rousse, Jean-Marie Tarascon, “Unveiling the electrochemical mechanisms of Li2Fe(SO4)2polymorphs by neutron diffraction and density functional theory calculations”, Phys Chem Chem Phys.18(21),14509-19(2016)R. Dominko, M. Bele, A. Kokalj, M. Gaberscek, J. Jamnik, “Li2MnSiO4as a potential Li-battery cathode material”, Journal of Power Sources.Volume174, Issue2, Pages 457-461 Figure 1 is a schematic cross-sectional view showing an example of the battery configuration according to the present disclosure.Figure 2 is a graph showing an example of the X-ray diffraction pattern of a negative electrode active material layer composed of a BiNi thin film fabricated on nickel foil.Figure 3 is a schematic partially enlarged cross-sectional view showing a modified example of the negative electrode of a battery according to the present disclosure.Figure 4 is a schematic cross-sectional view showing a modified example of the battery according to the present disclosure.Figure 5 shows the results of a charge-discharge test of the test cell according to Example 1, and is a graph showing the voltage during discharge and the discharge capacity per unit mass of positive electrode active material.Figure 6 shows the results of a charge-discharge test of the test cell according to Example 2, and is a graph showing the voltage during discharge and the discharge capacity per unit mass of positive electrode active material.Figure 7 shows the results of a charge-discharge test of the test cell according to Reference Example 1, and is a graph showing the voltage during discharge and the discharge capacity per unit mass of positive electrode active material.Figure 8 shows the results of a charge-discharge test of the test cell according to Reference Example 2, and is a graph showing the voltage during discharge and the discharge capacity per unit mass of positive electrode active material.Figure 9 shows the results of a charge-discharge test of the test cell according to Reference Example 3, and is a graph showing the voltage during discharge and the discharge capacity per unit mass of positive electrode active material. (Knowledge that forms the basis of this disclosure) As described in the [Background Technology] section, improvements in lithium secondary batteries are being made to battery characteristics by improving the electrode active material. When lithium metal is used as the negative electrode active material, a lithium secondary battery with high energy density per unit weight and per unit volume can be obtained. However, in lithium secondary batteries with this configuration, lithium deposits in a dendrite-like manner during charging. Because some of the deposited lithi