硅酸盐学报

B和Al复合掺杂对尖晶石型LiMn₂O₄单晶形貌及电化学性能的影响

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时龙 ¹ , 杨永胜 ¹ , 罗宇旭 ² , 郭俊明 ¹ , 王开坤 ³

硅酸盐学报 | 研究论文 2025,53(11): 3339-3351

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硅酸盐学报 |研究论文 2025 , 53 (11) : 3339 -3351

B和Al复合掺杂对尖晶石型LiMn₂O₄单晶形貌及电化学性能的影响

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时龙¹, 杨永胜¹, 罗宇旭², 郭俊明¹, 王开坤³

作者信息

^1．昭通学院化学化工学院，云南昭通 657000

^2．云南民族大学化学与环境学院，昆明 650500

^3．北京科技大学材料科学与工程学院，北京 100083

通讯作者:

杨永胜（1971—），男，博士，副教授；

郭俊明（1962—），男，硕士，教授。

作者简介:

时龙（1984—），男，博士，副教授。

Effect of B and Al co-Doping on Single-Crystal Morphology and Electrochemical Property of Spinel LiMn₂O₄

Long SHI¹, Yongsheng YANG¹, Yuxu LUO², Junming GUO¹, Kaikun WANG³

Affiliations

^1.School of Chemistry and Chemical Engineering, Zhaotong University, Zhaotong 657000, Yunnan, China

^2.School of Chemistry and Environment, Yunnan Minzu University, Kunming 650500, China

^3.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

Corresponding Author:

YANG Yongsheng (1971-), male, Ph.D., Associate Professor. E-mail: 943873392@qq.com;

GUO Junming (1962-), male, Master, Professor. guojunming@tsinghua.org.cn

SHI Long (1984-), male, Ph.D., Associate Professor. E-mail: shilong198408@163.com

出版时间: 2025-11-20 doi: 10.14062/j.issn.0454-5648.20250107

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摘要

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为改善尖晶石LiMn₂O₄的循环稳定性，抑制其容量衰减，采用固相燃烧法合成了B—Al共掺截断八面体形貌LiB_0.08Al_yMn_1.92-_yO₄（y=0.01、0.02、0.04、0.06和0.08）正极材料。结果表明，B—Al复合掺杂没有改变LiMn₂O₄的立方尖晶石结构，但可显著影响其晶面生长速率，促进材料的晶体生长和晶面的择优生长，且颗粒尺寸增大。在B—Al共掺杂中随Al掺杂量增加，颗粒形貌由包含（111）和（100）2个晶面的截断八面体逐渐形成包含（111）、（100）和（110）3个晶面的单晶截断八面体，y（Al）≥0.04时形成类球形颗粒，其中，LiB_0.08Al_0.02Mn_1.90O₄样品形成3个晶面的完整单晶截断八面体形貌颗粒，具有优良的倍率性能和长循环稳定性。在室温1.0、10.0、15.0 C倍率和高温（55 ℃）1.0 C倍率下，其初始放电比容量分别为114.7、86.3、82.6 mA·h·g^-1和114.7 mA·h·g^-1；1.0 C倍率200次循环、10.0 C和15.0 C倍率500次循环以及高温（55 ℃）1.0 C倍率200次循环后，容量保持率分别为84.7%、81.9%、90.3%和70.0%。LiB_0.08Al_0.02Mn_1.90O₄电极材料具有较大的锂离子扩散系数（3.14×10^-11 cm²·s^-1）以及相对较小的表观活化能（24.76 kJ/mol）和电荷转移阻抗（114.2 Ω），有利于锂离子的输运。B—Al共掺杂和单晶截断八面体形貌抑制了Jahn-Teller畸变并缓解Mn的溶解，提高了尖晶石型LiMn₂O₄正极材料的晶体结构稳定性，增强了材料的高倍率性能和长循环稳定性。

关键词

尖晶石锰酸锂 / 硼铝共掺杂 / 正极材料 / 截断八面体 / 晶面调控

Abstract

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Introduction

Rechargeable lithium-ion batteries (LIBs) are critical energy storage devices widely used in smartphones, electric vehicles, and hybrid vehicles due to their high efficiency and versatility. Spinel LiMn₂O₄ stands out as a promising cathode material owing to its eco-friendliness, safety, and cost-effectiveness. However, its practical application is limited by rapid capacity fading during cycling, especially under high current densities or elevated temperatures (55 ℃), caused by Jahn-Teller (J-T) distortion, Mn³⁺ dissolution, and oxygen defects. To address these issues, doping LiMn₂O₄ with elements like Al³⁺, B³⁺, Ni²⁺, or Mg²⁺ is a common strategy to stabilize Mn's average oxidation state (+3.5) and suppress J-T distortion. Concurrently, crystal facet engineering optimizes performance: truncated octahedral particles with dominant (111) facets (low surface energy, dense Mn packing) minimize Mn dissolution, while (100)/(110) facets enhance Li⁺ mobility for improved rate capability. Combining doping and facet control has emerged as a key research focus. For instance, B-doped LiMn_1.96B_0.06O₄ exhibited 110.3 mA·h·g^-1 at 5.0 C with 51.8% capacity retention after 2000 cycles, outperforming undoped LiMn₂O₄. Ni—B co-doping further refined morphology and boosted retention to 70.6%. Similarly, Mg—Al co-doped LiMg_0.03Al_0.10Mn_1.87O₄ retained 76.2% capacity after 1000 cycles at 10.0 C, while Zn—Al doping achieved 70%-75% retention over 2000 cycles. These studies highlight how doping regulates crystal growth, favoring truncated octahedral morphologies with balanced stability and kinetics. Building on this, our work synthesizes LiB_0.08Al_yMn_1.92-_yO₄ (y=0.01, 0.02, 0.04, 0.06, 0.08) via solid-state combustion to study Al doping's impact. Results reveal that Al content modulates facet growth: low doping levels yield two-facet (111/100) truncated octahedrons, while higher doping introduces (110) facets, ultimately leading to quasi-spherical particles. This controlled facet producing strategy is designed to optimize structural stability and electrochemical performance for advanced LIBs.

Methods

LiB_0.08Mn_1.92O₄ and LiB_0.08Al_yMn_1.92-_yO₄ (y=0.01, 0.02, 0.04, 0.06, 0.08) were synthesized by stoichiometric mixing of Li₂CO₃, H₃BO₃, MnCO₃, and Al(OH)(CH₃COO)₂ (total 30 g) with 1.5 g citric acid as a combustion agent. The mixture was ball-milled in ethanol for 10 h, dried, and calcined at 500 ℃ for 1 h. After grinding, it was sintered at 650 ℃ for 6 h. Products were labeled as B_0.08 and B_0.08Al_y. Cathode slurry was prepared by blending active material, carbon black, and PVDF (8∶1∶1) with NMP solvent, followed by 30 min ball milling. The slurry was coated onto Al foil, dried at 80 ℃ for 4 h, and cut into 14 mm discs (active material loading: about 1.0 mg/cm²). CR2032 coin cells were assembled in an Ar-filled glovebox using Li metal anode, LiPF₆ electrolyte (1.0 M in EC/DMC/EMC), and Celgard 2320 separator. Material phases were analyzed via XRD (Cu K_α, 10°-80°). Morphology and microstructure were examined by FE-SEM and TEM. Surface composition and valence states were determined via XPS. Electrochemical tests (Land CT2001A) included cycling (25/55 ℃, 3.0-4.5 V) and rate performance. CV and EIS were conducted using a CHI604D workstation.

Results and discussion

XRD analysis confirmed that B_0.08 and B—Al co-doped samples crystallized in the spinel LiMn₂O₄ structure (). B—Al co-doping enhanced crystallinity, with diffraction peaks intensifying until y(Al)≥0.06, beyond which crystallinity declined. A lattice contraction was observed via (400) peak shifts, attributed to smaller B³⁺/Al³⁺(0.0400/0.0535 nm) replacing Mn³⁺(0.0645 nm) and shorter B/Al—O bonds, suppressing J-T distortion. SEM revealed that B—Al co-doping refined particle uniformity and morphology: B_0.08Al_0.02 exhibited truncated octahedral single-crystals with high (111) and minor (100)/(110) facets, while higher Al content (y≥0.04) led to spherical polyhedrons due to reduced facet growth rates. TEM/SAED confirmed improved crystallinity for B_0.08Al_0.02, with distinct lattice fringes (0.476 nm for (111)) and ordered diffraction patterns. XPS verified B³⁺/Al³⁺ incorporation and a higher Mn⁴⁺ ratio (B_0.08Al_0.02∶ Mn³⁺/Mn⁴⁺=47.29%/52.71%), stabilizing the Mn—O framework. Electrochemical tests demonstrated superior performance for B_0.08Al_0.02∶ At 5.0 C, it retained 83.9% capacity after 500 cycles (vs. 71.3% for B_0.08) due to suppressed Mn dissolution and enhanced Li⁺ transport from truncated octahedral morphology. High-rate testing (15.0 C, 20.0 C) showed B_0.08Al_0.02 retained 77.2% capacity after 500 cycles, outperforming B_0.08 (58.2%). Elevated-temperature (55 ℃) cycling revealed B_0.08Al_0.02 maintained 70% capacity retention (200 cycles), attributed to reduced side reactions and structural stability. CV and EIS confirmed faster Li⁺ diffusion (D_Li⁺: 3.14×10^-11 cm²·s^-1) and lower charge-transfer resistance for B_0.08Al_0.02. Kinetic analysis showed a lower activation energy (24.76 kJ/mol vs. 28.53 kJ/mol for B_0.08), indicating an enhanced reaction kinetics.

Conclusions

B—Al co-doped LiB_0.08Al_yMn_1.92-_yO₄ (y=0.01, 0.02, 0.04, 0.06, 0.08) cathode materials were synthesized via solid-phase combustion. B—Al co-doping enhanced crystal growth and facet evolution: particles transitioned from truncated octahedrons with two facets (111, 100) to those incorporating (111), (100), and (110) facets as Al content increased. At y(Al)≥0.04, spherical-like polyhedrons dominated. The optimized LiB_0.08Al_0.02Mn_1.90O₄ (B_0.08Al_0.02) exhibited superior crystallinity and well-defined truncated octahedral single-crystals. B_0.08Al_0.02 demonstrated exceptional rate capability and cycling stability. At 1.0 C, 5.0 C, 10.0 C, 15.0 C, 20.0 C, and 55 ℃/5.0 C, initial discharge capacities reached 114.7, 102.8, 86.3, 82.6, 75.3, and 107.4 mA·h·g^-1, respectively. After 500 cycles, capacity retention rates were 83.9% (5.0 C), 81.9% (10 C), 90.3% (15.0 C), 77.2% (20.0 C), and 62.0% (55 ℃/5.0 C), outperforming other samples. CV and EIS analyses demonstrated superior electrochemical properties for the B_0.08Al_0.02, including a higher Li⁺ diffusion coefficient (3.14×10^-11 cm²·s^-1), a lower apparent activation energy (24.76 kJ/mol), and a reduced charge-transfer resistance (114.2 Ω). These results indicate enhanced Li⁺ transport kinetics and improved structural stability.

Key words

spinel lithium manganese oxide / boron-aluminum co-doping / cathode material / truncated octahedron / crystal plane regulation

引用本文

时龙, 杨永胜, 罗宇旭, 郭俊明, 王开坤. B和Al复合掺杂对尖晶石型LiMn₂O₄单晶形貌及电化学性能的影响. 硅酸盐学报, 2025 , 53 (11) : 3339 -3351 . DOI: 10.14062/j.issn.0454-5648.20250107

Long SHI, Yongsheng YANG, Yuxu LUO, Junming GUO, Kaikun WANG. Effect of B and Al co-Doping on Single-Crystal Morphology and Electrochemical Property of Spinel LiMn₂O₄[J]. Journal of the Chinese Ceramic Society, 2025 , 53 (11) : 3339 -3351 . DOI: 10.14062/j.issn.0454-5648.20250107

基金

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国家自然科学基金(51972282)
云南省院士（专家）工作站项目(202405AF140034)
昭通学院博士科研启动经费项目

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2025年第53卷第11期

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文章信息

doi: 10.14062/j.issn.0454-5648.20250107

接收时间：2025-02-19
首发时间：2026-10-21
出版时间：2025-11-20

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出版历史

收稿日期：2025-02-19
修回日期：2025-03-09

基金

国家自然科学基金(51972282)

云南省院士（专家）工作站项目(202405AF140034)

昭通学院博士科研启动经费项目

作者信息

^1．昭通学院化学化工学院，云南昭通 657000

^2．云南民族大学化学与环境学院，昆明 650500

^3．北京科技大学材料科学与工程学院，北京 100083

通讯作者:

杨永胜（1971—），男，博士，副教授；

郭俊明（1962—），男，硕士，教授。

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2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

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