Recent advances and practical challenges of high-energy-density flexible lithium-ion batteries

Abstract

With the rapid iteration and update of wearable flexible devices, high-energy-density flexible lithium-ion batteries are rapidly thriving. Flexibility, energy density, and safety are all important indicators for flexible lithium-ion batteries, which can be determined jointly by material selection and structural design. Here, recent progress on high-energy-density electrode materials and flexible structure designs are discussed. Commercialized electrode materials and the next-generation high-energy-density electrode materials are analyzed in detail. The electrolytes with high safety and excellent flexibility are classified and discussed. The strategies to increase the mass loading of active materials on the electrodes by designing the current collector and electrode structure are discussed with keys of representative works. And the novel configuration structures to enhance the flexibility of batteries are displayed. In the end, it is pointed out that it is necessary to quantify the comprehensive performance of flexible lithium-ion batteries and simultaneously enhance the energy density, flexibility, and safety of batteries for the development of the next-generation high-energy-density flexible lithium-ion batteries.

Key words： lithium-ion batteries; flexibility; high energy density; safety

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

The authors acknowledge and thank for financial support from the National Natural Science Foundation of China (Grant No. 52302234), the China Postdoctoral Science Foundation (Grant No. 2022M710950), the Heilongjiang Provincial Postdoctoral Science Foundation (Grant No. LBH-Z21131), and the Natural Science of Heilongjiang Province (Grant No. LH2023B009).

References

1 Chang J , Huang Q , Gao Y , Zheng Z . Pathways of developing high-energy-density flexible lithium batteries. Advanced Materials, 2021, 33(46): 2004419

2 Wang M , Luo Y , Wang T , Wan C , Pan L , Pan S , He K , Neo A , Chen X . Artificial skin perception. Advanced Materials, 2021, 33(19): 2003014

3 Zhou G , Li F , Cheng H M . Progress in flexible lithium batteries and future prospects. Energy & Environmental Science, 2014, 7(4): 1307–1338

4 Kim S H , Kim N Y , Choe U J , Kim J M , Lee Y G , Lee S Y . Ultrahigh-energy-density flexible lithium-metal full cells based on conductive fibrous skeletons. Advanced Energy Materials, 2021, 11(24): 2100531

5 Wang Z , Zhang W , Li X , Gao L . Recent progress in flexible energy storage materials for lithium-ion batteries and electrochemical capacitors: a review. Journal of Materials Research, 2016, 31(12): 1648–1664

6 Alahmed A , Sabir E C . Textile based electrodes for flexible lithium-ion batteries: new updates. Current Nanoscience, 2022, 18(6): 659–667

7 Zeng L , Qiu L , Cheng H M . Towards the practical use of flexible lithium ion batteries. Energy Storage Materials, 2019, 23: 434–438

8 Deng L , Wei T , Liu J , Zhan L , Chen W , Cao J . Recent developments of carbon-based anode materials for flexible lithium-ion batteries. Crystals, 2022, 12(9): 1279

9 Zhang X . Thermal analysis of a cylindrical lithium-ion battery. Electrochimica Acta, 2011, 56(3): 1246–1255

10 Deng J , Smith I , Bae C , Rairigh P , Miller T , Surampudi B . Communication-impact behaviors of pouch and prismatic battery modules. Journal of the Electrochemical Society, 2021, 168(2): 020520

11 Ostfeld A E , Gaikwad A M , Khan Y , Arias A C . High-performance flexible energy storage and harvesting system for wearable electronics. Scientific Reports, 2016, 6(1): 26122

12 Xie C , Guo Y , Zheng Z . Pushing the limit of flexible batteries. CCS Chemistry, 2023, 5(3): 531–543

13 Fu K K , Cheng J , Li T , Hu L . Flexible batteries: from mechanics to devices. ACS Energy Letters, 2016, 1(5): 1065–1079

14 Liang G , Mo F , Yang Q , Huang Z , Li X , Wang D , Liu Z , Li H , Zhang Q , Zhi C . Commencing an acidic battery based on a copper anode with ultrafast proton-regulated kinetics and superior dendrite-free property. Advanced Materials, 2019, 31(52): 1905873

15 Lu X , Cheng J , Zhou D , Chen Y , Jiang H , Lu Y , Zhang D , Kong D , Chu P K , Yang H Y . . Highly flexible multilayer MXene hollow carbon nanofibers confined with Fe₃C particles for high-performance lithium-ion batteries. Chemical Engineering Journal, 2023, 478(15): 147366

16 Li H , Tang Z , Liu Z , Zhi C . Evaluating flexibility and wearability of flexible energy storage devices. Joule, 2019, 3(3): 613–619

17 Mao L , Meng Q , Ahmad A , Wei Z . Mechanical analyses and structural design requirements for flexible energy storage devices. Advanced Energy Materials, 2017, 7(23): 1700535

18 Zheng S , Shi D , Sun T , Zhang L , Zhang W , Li Y , Guo Z , Tao Z , Chen J . Hydrogen bond networks stabilized high-capacity organic cathode for lithium-ion batteries. Angewandte Chemie International Edition, 2023, 62(9): e202217710

19 Ge M , Cao C , Biesold G M , Sewell C D , Hao S M , Huang J , Zhang W , Lai Y , Lin Z . Recent advances in silicon-based electrodes: from fundamental research toward practical applications. Advanced Materials, 2021, 33(16): 2004577

20 Nagata H , Akimoto J , Kataoka K . Influence of compositing conditions for Si-composite negative electrodes in sulfide-type all-solid-state lithium-ion batteries. New Journal of Chemistry, 2023, 47(18): 8479–8483

21 Shang J , Yu W , Wang L , Xie C , Xu H , Wang W , Huang Q , Zheng Z . Metallic glass-fiber fabrics: a new type of flexible, super-lightweight, and 3D current collector for lithium batteries. Advanced Materials, 2023, 35(26): 2211748

22 Koo M , Park K I , Lee S H , Suh M , Jeon D Y , Choi J W , Kang K , Lee K J . Bendable inorganic thin-film battery for fully flexible electronic systems. Nano Letters, 2012, 12(9): 4810–4816

23 Xu S , Zhang Y , Cho J , Lee J , Huang X , Jia L , Fan J A , Su Y , Su J , Zhang H . . Stretchable batteries with self-similar serpentine interconnects and integrated wireless recharging systems. Nature Communications, 2013, 4(1): 1543

24 Ren J , Zhang Y , Bai W , Chen X , Zhang Z , Fang X , Weng W , Wang Y , Peng H . Elastic and wearable wire-shaped lithium-ion battery with high electrochemical performance. Angewandte Chemie International Edition, 2014, 53(30): 7864–7869

25 Liu Q C , Liu T , Liu D P , Li Z J , Zhang X B , Zhang Y . A flexible and wearable lithium-oxygen battery with record energy density achieved by the interlaced architecture inspired by bamboo slips. Advanced Materials, 2016, 28(38): 8413–8418

26 Qian G , Zhu B , Liao X , Zhai H , Srinivasan A , Fritz N J , Cheng Q , Ning M , Qie B , Li Y . . Bioinspired, spine-like, flexible, rechargeable lithium-ion batteries with high energy density. Advanced Materials, 2018, 30(12): 1704947

27 Meng Q , Kang C , Zhu J , Xiao X , Ma Y , Huo H , Zuo P , Du C , Lou S , Yin G . DNA helix structure inspired flexible lithium-ion batteries with high spiral deformability and long-lived cyclic stability. Nano Letters, 2022, 22(13): 5553–5560

28 Bao Y , Liu H , Zhao Z , Ma X , Zhang X Y , Liu G , Song W L . Toward flexible embodied energy: scale-inspired overlapping lithium-ion batteries with high-energy-density and variable stiffness. Advanced Functional Materials, 2023, 33(37): 2301581

29 Wang Y , Chen F , Liu Z , Tang Z , Yang Q , Zhao Y , Du S , Chen Q , Zhi C . A highly elastic and reversibly stretchable all polymer supercapacitor. Angewandte Chemie International Edition, 2019, 58(44): 15707–15711

30 Xu C , Fan Z , Zhang M , Wang P , Wang H , Jin C , Peng Y , Jiang F , Feng X , Ouyang M . A comparative study of the venting gas of lithium-ion batteries during thermal runaway triggered by various methods. Cell Reports. Physical Science, 2023, 4(12): 101705

31 Zhou Q , Dong S , Lv Z , Xu G , Huang L , Wang Q , Cui Z , Cui G . A temperature-responsive electrolyte endowing superior safety characteristic of lithium metal batteries. Advanced Energy Materials, 2020, 10(6): 1903441

32 Deng R , He T . Flexible solid-state lithium-ion batteries: materials and structures. Energies, 2023, 16(12): 4549

33 Kim B , Yang S H , Seo J H , Kang Y C . Inducing an amorphous phase in polymer plastic crystal electrolyte for effective ion transportation in lithium metal batteries. Advanced Functional Materials, 2023, 34(7): 2310957

34 Wang X , Lu X , Liu B , Chen D , Tong Y , Shen G . Flexible energy storage devices: design consideration and recent progress. Advanced Materials, 2014, 26(28): 4763–4782

35 Zhang S , Wang Y , He H , Huo F , Lu Y , Zhang X , Dong K . A new era of precise liquid regulation: quasi-liquid. Green Energy & Environment, 2017, 2(4): 329–330

36 Cai M , Dong Y , Xie M , Dong W , Dong C , Dai P , Zhang H , Wang X , Sun X , Zhang S . . Stalling oxygen evolution in high-voltage cathodes by lanthurization. Nature Energy, 2023, 8(2): 159–168

37 Wang C Y , Zheng Z J , Feng Y Q , Ye H , Cao F F , Guo Z P . Topological design of ultrastrong MXene paper hosted Li enables ultrathin and fully flexible lithium metal batteries. Nano Energy, 2020, 74: 104817

38 Aliahmad N , Biswas P K , Dalir H , Agarwal M . Synthesis of V₂O₅/single-walled carbon nanotubes integrated into nanostructured composites as cathode materials in high performance lithium-ion batteries. Energies, 2022, 15(2): 552

39 Cho S J , Choi K H , Yoo J T , Kim J H , Lee Y H , Chun S J , Park S B , Choi D H , Wu Q , Lee S Y . . Hetero-nanonet rechargeable paper batteries: toward ultrahigh energy density and origami foldability. Advanced Functional Materials, 2015, 38(25): 6029–6040

40 Weng W , Sun Q , Zhang Y , He S , Wu Q , Deng J , Fang X , Guan G , Ren J , Peng H . A gum-like lithium-ion battery based on a novel arched structure. Advanced Materials, 2015, 27(8): 1363–1369

41 Kammoun M , Berg S , Ardebili H . Flexible thin-film battery based on graphene-oxide embedded in solid polymer electrolyte. Nanoscale, 2015, 7(41): 17516–17522

42 Zheng S , Wu Z S , Zhou F , Wang X , Ma J , Liu C , He Y B , Bao X . All-solid-state planar integrated lithium-ion micro-batteries with extraordinary flexibility and high-temperature performance. Nano Energy, 2018, 51: 613–620

43 Cui J , Yao S , Chong W G , Wu J , Ihsan-Ul-Haq M , Ma L , Zhao M , Wang Y , Kim J K . Ultrafast Li⁺ diffusion kinetics of 2D oxidized phosphorus for quasi-solid-state bendable batteries with exceptional energy densities. Chemistry of Materials, 2019, 31(11): 4113–4123

44 Xu J , Cai X , Cai S , Shao Y , Hu C , Lu S , Ding S . High-energy lithium-ion batteries: recent progress and a promising future in applications. Energy & Environmental Materials, 2023, 6(5): e12450

45 Xu D , Liang M , Qi S , Sun W , Lv L P , Du F H , Wang B , Chen S , Wang Y , Yu Y . The progress and prospect of tunable organic molecules for organic lithium-ion batteries. ACS Nano, 2021, 15(1): 47–80

46 Park H , Shuku Y , Lee J , Lee K , Joo M D , An B K , Awaga K , Young P S , Eon K J . Isomeric triptycene triquinones as universal cathode materials for high energy alkali metal batteries. Batteries & Supercaps, 2023, 6(3): e202200497

47 Chen H , Armand M , Demailly G , Dolhem F , Poizot P , Tarascon J M . From biomass to a renewable LiXC₆O₆ organic electrode for sustainable Li-ion batteries. ChemSusChem, 2008, 1(4): 348–355

48 Li K , Yu J , Si Z , Gao B , Wang H , Wang Y . W H, Wang Y. One-dimensional π-d conjugated coordination polymer with double redox-active centers for all-organic symmetric lithium-ion batteries. Chemical Engineering Journal, 2022, 450: 138052

49 Lu Y , Zhang Q , Li L , Niu Z , Chen J . Design strategies toward enhancing the performance of organic electrode materials in metal-ion batteries. Chem, 2018, 4(12): 2786–2813

50 Zhao F , Zhao X , Peng B , Gan F , Yao M , Tan W , Dong J , Zhang Q . Polyimide-derived carbon nanofiber membranes as anodes for high-performance flexible lithium-ion batteries. Chinese Chemical Letters, 2018, 29(11): 1692–1697

51 Wang X , Liu B , Hou X , Wang Q , Li W , Chen D , Shen G . Ultralong-life and high-rate web-like Li₄Ti₅O₁₂ anode for high-performance flexible lithium-ion batteries. Nano Research, 2014, 7(7): 1073–1082

52 Li P , Kim H , Ming J , Jung H-G , Belharouak I , Sun Y K . Quasi-compensatory effect in emerging anode-free lithium batteries. eScience, 2021, 1(1): 3–12

53 Zhang Y , Yi L , Zhang J , Wang X , Hu X , Wei W , Wang H . Advances in flexible lithium metal batteries. Science China Materials, 2022, 65(8): 2035–2059

54 Zhang X , Yang Y , Zhou Z . Towards practical lithium-metal anodes. Chemical Society Reviews, 2020, 49(10): 3040–3071

55 Gao J , Chen C , Dong Q , Dai J , Yao Y , Li T , Rundlett A , Wang R , Wang C , Hu L . Stamping flexible Li alloy anodes. Advanced Materials, 2021, 33(11): 2005305

56 Qing P , Wu Z , Wang A , Huang S , Long K , Naren T , Chen D , He P , Huang H , Chen Y . . Highly reversible lithium metal anode enabled by 3D lipophilic-lithophytic dual-skeletons. Advanced Materials, 2023, 35(15): 2211203

57 Kim J M , Engelhard M H , Lu B , Xu Y , Tan S , Matthews B E , Tripathi S , Cao X , Niu C , Hu E . . High current-density-charging lithium metal batteries enabled by double-layer protected lithium metal anode. Advanced Functional Materials, 2022, 32(48): 2207172

58 Kim J H , Lee Y H , Cho S J , Gwon J G , Cho H J , Jang M , Lee S Y , Lee S Y . Nanomat Li-S batteries based on all-fibrous cathode/separator assemblies and reinforced Li metal anodes: towards ultrahigh energy density and flexibility. Energy & Environmental Science, 2019, 12(1): 177–186

59 Liu T , Feng X L , Jin X , Shao M Z , Su Y T , Zhang Y , Zhang X B . Protecting the lithium metal anode for a safe flexible lithium air battery in ambient air. Angewandte Chemie International Edition, 2019, 58(50): 18240–18245

60 Zhang S , Liang T , Wang D , Xu Y , Cui Y , Li J , Wang X , Xia X , Gu C , Tu J . A stretchable and safe polymer electrolyte with a protecting-layer strategy for solid-state lithium metal batteries. Advanced Science, 2021, 8(15): 2003241

61 Wang H , Fu J , Wang C , Wang J , Yang A , Li C , Sun Q , Yi C , Li H . A binder-free high silicon content flexible anode for Li-ion batteries. Energy & Environmental Science, 2020, 13(3): 848–858

62 Salvatierra R V , Raji A R O , Lee S K , Ji Y , Li L , Tour J M . Silicon nanowires and lithium cobalt oxide nanowires in graphene nanoribbon papers for full lithium ion battery. Advanced Energy Materials, 2016, 6(24): 1600918

63 Mu Y , Han M , Wu B , Wang Y , Zi L , Li J , Li Z , Wang S , Wan J , Zeng L . Nitrogen, oxygen-codoped vertical graphene arrays coated 3D flexible carbon nanofibers with high silicon content as an ultrastable anode for superior lithium storage. Advanced Science, 2022, 9(6): 2104685

64 An Y , Tian Y , Liu C , Xiong S , Feng J , Qian Y . One-step, vacuum-assisted construction of micrometer-sized nanoporous silicon confined by uniform two-dimensional N-doped carbon toward advanced Li-ion and MXene-based Li metal batteries. ACS Nano, 2022, 16(3): 4560–4577

65 Huo S , Sheng L , Xue W , Wang L , Xu H , Zhang H , He X . Challenges of polymer electrolyte with wide electrochemical window for high energy solid-state lithium batteries. InfoMat, 2023, 5(3): e12394

66 Fang R , Li Y , Wu N , Xu B , Liu Y , Manthiram A , Goodenough J B . Ultra-thin single-particle-layer sodium beta-alumina-based composite polymer electrolyte membrane for sodium-metal batteries. Advanced Functional Materials, 2023, 33(6): 2211229

67 Xu P , Shuang Z Y , Zhao C Z , Li X , Fan L Z , Chen A , Chen H , Kuzmina E , Karaseva E , Kolosnitsyn V . . A review of solid-state lithium metal batteries through in-situ solidification. Science China. Chemistry, 2024, 67(1): 7–86

68 Son J M , Oh S , Bae S H , Nam S , Oh K . A pair of NiCo₂O₄ and V₂O₅ nanowires directly grown on carbon fabric for highly bendable lithium-ion batteries. Advanced Energy Materials, 2019, 9(18): 1900477

69 Ha S H , Shin K H , Park H W , Lee Y J . Flexible lithium-ion batteries with high areal capacity enabled by smart conductive textiles. Small, 2018, 14(43): 1703418

70 Chen H , Zheng M , Qian Sh , Ling H Y , Wu Z , Liu X , Yan C , Zhang S . Functional additives for solid polymer electrolytes in flexible and high-energy-density solid-state lithium-ion batteries. Carbon Energy, 2021, 3(6): 929–956

71 Fang R , Liu Y , Li Y , Manthiram A , Goodenough J B . Achieving stable all-solid-state lithium-metal batteries by tuning the cathode-electrolyte interface and ionic/electronic transport within the cathode. Materials Today, 2023, 64: 52–60

72 Yang S J , Hu J K , Jiang F N , Yuan H , Park H S , Huang J Q . Safer solid-state lithium metal batteries: mechanisms and strategies. InfoMat, 2023, 6(2): e12512

73 Tufail M K , Ahmed A , Rafiq M , Asif N M , Shoaib A S S , Sohail M , Sufyan J M , Najam T , Althomali R H , Rahman M M . Chemistry aspects and designing strategies of flexible materials for high-performance flexible lithium-ion batteries. Chemical Record, 2023, 24(1): e202300155

74 Liu Y N , Xiao Z , Zhang W K , Zhang J , Huang H , Gan Y P , He X P , Kumar G G , Xia Y . Poly(m-phenylene isophthalamide)-reinforced polyethylene oxide composite electrolyte with high mechanical strength and thermostability for all-solid-state lithium metal batteries. Rare Metals, 2022, 41(11): 3762–3773

75 Wang S , Xiong P , Zhang J , Wang G . Recent progress on flexible lithium metal batteries: composite lithium metal anodes and solid-state electrolytes. Energy Storage Materials, 2020, 29: 310–331

76 Su Y , Xu F , Zhang X , Qiu Y , Wang H . Rational design of high-performance PEO/ceramic composite solid electrolytes for lithium metal batteries. Nano-Micro Letters, 2023, 15(1): 82

77 Fang R , Xu H , Xu B , Li X , Li Y , Goodenough J B . Reaction mechanism optimization of solid-state Li-S batteries with a PEO-based electrolyte. Advanced Functional Materials, 2021, 31(2): 2001812

78 Xia Y , Wang Q , Liu Y , Zhang J , Xia X , Huang H , Gan Y , He X , Xiao Z , Zhang W . Three-dimensional polyimide nanofiber framework reinforced polymer electrolyte for all-solid-state lithium metal battery. Journal of Colloid and Interface Science, 2023, 638: 908–917

79 Xie H , Yang C , Fu K K , Yao Y , Jiang F , Hitz E , Liu B , Wang S , Hu L . Flexible, scalable, and highly conductive garnet-polymer solid electrolyte templated by bacterial cellulose. Advanced Energy Materials, 2018, 8(18): 1703474

80 Shen W , Li K , Lv Y , Xu T , Wei D , Liu Z . Highly-safe and ultra-stable all-flexible gel polymer lithium ion batteries aiming for scalable applications. Advanced Energy Materials, 2020, 10(21): 1904281

81 Yusim Y , Trevisanello E , Ruess R H , Richter F , Mayer A , Bresser D , Passerini S , Janek J , Henss A . Evaluation and improvement of the stability of poly(ethylene oxide)-based solid-state batteries with high-voltage cathodes. Angewandte Chemie International Edition, 2023, 12(62): e202218316

82 Thomas M L , Kan H S , Nanbu S , Masahiro Y F . Organic ionic plastic crystals: flexible solid electrolytes for lithium secondary batteries. Energy Advances, 2023, 2(6): 748–764

83 Wan J , Xie J , Kong X , Liu Z , Liu K , Shi F , Pei A , Chen H , Chen W , Chen J . . Ultrathin, flexible, solid polymer composite electrolyte enabled with aligned nanoporous host for lithium batteries. Nature Nanotechnology, 2019, 14(7): 705–711

84 Wang Z , Shen L , Deng S , Cui P , Yao X . 10 μm-thick high-strength solid polymer electrolytes with excellent interface compatibility for flexible all-solid-state lithium-metal batteries. Advanced Materials, 2021, 33(25): 2100353

85 Lopez J , Mackanic D G , Cui Y , Bao Z . Designing polymers for advanced battery chemistries. Nature Reviews. Materials, 2019, 4(5): 4312–4330

86 Wu N , Shi Y R , Lang S Y , Zhou J M , Liang J Y , Wang W , Tan S J , Yin Y X , Wen R , Guo Y G . Self-healable solid polymeric electrolytes for stable and flexible lithium metal batteries. Angewandte Chemie International Edition, 2019, 58(50): 18146–18149

87 Ha H J , Kil E H , Kwon Y H , Kim J Y , Lee C K , Lee S Y . UV-curable semi-interpenetrating polymer network-integrated, highly bendable plastic crystal composite electrolytes for shape-conformable all-solid-state lithium ion batteries. Energy & Environmental Science, 2012, 5(4): 6491–6499

88 Ho C K , Ju C S , Hee K S , Han K Y , Young K J , Young L S . Thin, deformable, and safety-reinforced plastic crystal polymer electrolytes for high-performance flexible lithium-ion batteries. Advanced Functional Materials, 2014, 24(1): 44–52

89 Chen G , Zhang F , Zhou Z , Li J , Tang Y . A flexible dual-ion battery based on PVDF-HFP-modified gel polymer electrolyte with excellent cycling performance and superior rate capability. Advanced Energy Materials, 2018, 8(25): 1801219

90 Chi X , Li M , Di J , Bai P , Song L , Wang X , Li F , Liang S , Xu J , Yu J . A highly stable and flexible zeolite electrolyte solid-state Li-air battery. Nature, 2021, 592(7855): 551–557

91 Wu Q , Yang Y , Ma C , Chen Z , Su Q , Zhu C , Gao Y , Ma R , Li C . Flexible nanocomposite polymer electrolyte based on UV-cured polyurethane acrylate for lithium metal batteries. ACS Sustainable Chemistry & Engineering, 2021, 9(16): 5631–5641

92 Pan K , Zhang L , Qian W , Wu X , Dong K , Zhang H , Zhang S . A flexible ceramic/polymer hybrid solid electrolyte for solid state lithium metal batteries. Advanced Materials, 2020, 32(17): 2000399

93 Jiang T , He P , Wang G , Shen Y , Nan C W , Fan L Z . Solvent-free synthesis of thin, flexible, nonflammable garnet-based composite solid electrolyte for all-solid-state lithium batteries. Advanced Energy Materials, 2020, 10(12): 1903376

94 Liu Y , Li Y , Sun J , Du Z , Hu X , Bi J , Liu C , Ai W , Yan Q . Present and future of functionalized Cu current collectors for stabilizing lithium metal anodes. Nano Research Energy, 2023, 2: e9120048

95 Fu A , Wang C , Peng J , Su M , Pei F , Cui J , Fang X , Li J F , Zheng N . Lithiophilic and antioxidative copper current collectors for highly stable lithium metal batteries. Advanced Functional Materials, 2021, 31(15): 2009805

96 Liu P , Wang Y , Hao H , Basu S , Feng X , Xu Y , Boscoboinik J A , Nanda J , Watt J , Mitlin D . Stable potassium metal anodes with an all-aluminum current collector through improved electrolyte wetting. Advanced Materials, 2020, 32(49): 2002908

97 Park M H , Noh M , Lee S , Ko M , Chae S , Sim S , Choi S , Kim H , Nam H , Park S . . Flexible high-energy Li-ion batteries with fast-charging capability. Nano Letters, 2014, 14(7): 4083–4089

98 Shang K , Gao J , Yin X , Ding Y , Wen Z . An overview of flexible electrode materials/substrates for flexible electrochemical energy storage/conversion devices. European Journal of Inorganic Chemistry, 2021, 7(7): 606–619

99 Li N , Chen Z , Ren W , Li F , Cheng H M . Flexible graphene-based lithium ion batteries with ultrafast charge and discharge rates. Proceedings of the National Academy of Sciences of the United States of America, 2012, 109(43): 17360–17365

100 Wu F , Gao X , Xu X , Jiang Y , Gao X , Yin R , Shi W , Liu W , Lu G , Cao X . Carbon cloth for flexible aqueous zinc-ion batteries. ChemSusChem, 2020, 13(6): 1537–1545

101 Shi H , Wen G , Nie Y , Zhang G , Duan H . Flexible 3D carbon cloth as a high-performing electrode for energy storage and conversion. Nanoscale, 2020, 12(9): 5261–5285

102 Kordek K , Jiang L , Fan K , Zhu Z , Xu L , Al-Mamun M , Dou Y , Chen S , Liu P , Yin H , Rutkowski P , Zhao H . Two-step activated carbon cloth with oxygen-rich functional groups as a high-performance additive-free air electrode for flexible zinc-air batteries. Advanced Energy Materials, 2019, 9(4): 1802936

103 Balogun M S , Qiu W , Lyu F , Luo Y , Meng H , Li J , Mai W , Mai L , Tong Y . All-flexible lithium ion battery based on thermally-etched porous carbon cloth anode and cathode. Nano Energy, 2016, 26: 446–455

104 Balogun M S , Yang H , Luo Y , Qiu W , Huang Y , Liu Z Q , Tong Y . Achieving high gravimetric energy density for flexible lithium-ion batteries facilitated by core-double-shell electrodes. Energy & Environmental Science, 2018, 11(7): 1859–1869

105 Zhu S , Sheng J , Chen Y , Ni J , Li Y . Carbon nanotubes for flexible batteries: recent progress and future perspective. National Science Review, 2021, 8(5): nwaa261

106 Fang B , Chang D , Xu Z , Gao C . A review on graphene fibers: expectations, advances, and prospects. Advanced Materials, 2020, 32(5): 1902664

107 Hu L , Wu H , La M F , Yang Y , Cui Y . Thin, flexible secondary Li-ion paper batteries. ACS Nano, 2010, 4(10): 5843–5848

108 Hu J W , Wu Z P , Zhong S W , Zhang W B , Suresh S , Mehta A , Koratkar N . Folding insensitive, high energy density lithium-ion battery featuring carbon nanotube current collectors. Carbon, 2015, 87: 292–298

109 Wang K , Luo S , Wu Y , He X , Zhao F , Wang J , Jiang K , Fan S . Super-aligned carbon nanotube films as current collectors for lightweight and flexible lithium ion batteries. Advanced Functional Materials, 2013, 23(7): 846–853

110 Gaikwad A M , Khau B V , Davies G , Hertzberg B , Steingart D A , Arias A C . A high areal capacity flexible lithium-ion battery with a strain-compliant design. Advanced Energy Materials, 2015, 5(3): 1401389

111 Zhang M , Li J , Sun C , Wang Z , Li Y , Zhang D . Durable flexible dual-layer and free-standing silicon/carbon composite anode for lithium-ion batteries. Journal of Alloys and Compounds, 2023, 932: 167687

112 Balogun M S , Yu M , Huang Y , Li C , Fang P , Liu Y , Lu X , Tong Y . Binder-free Fe₂N nanoparticles on carbon textile with high power density as novel anode for high-performance flexible lithium ion batteries. Nano Energy, 2015, 11: 348–355

113 Balogun M S , Wu Z , Luo Y , Qiu W , Fan X , Long B , Huang M , Liu P , Tong Y . High power density nitridated hematite (α-Fe₂O₃) nanorods as anode for high-performance flexible lithium ion batteries. Journal of Power Sources, 2016, 308: 7–17

114 Hwang C , Song W J , Han J G , Bae S , Song G , Choi N S , Park S , Song H K . Foldable electrode architectures based on silver-nanowire-wound or carbon-nanotube-webbed micrometer-scale fibers of polyethylene terephthalate mats for flexible lithium-ion batteries. Advanced Materials, 2018, 30(7): 1705445

115 Mo F , Liang G , Huang Z , Li H , Wang D , Zhi C . An overview of fiber-shaped batteries with a focus on multifunctionality, scalability, and technical difficulties. Advanced Materials, 2020, 32(5): 1902151

116 Fang Z , Wang J , Wu H , Li Q , Fan S , Wang J . Progress and challenges of flexible lithium ion batteries. Journal of Power Sources, 2020, 454: 227932

117 Ke R , Du L , Han B , Xu H , Meng H , Zeng H , Zheng Z , Deng Y . Biobased self-growing approach toward tailored, integrated high-performance flexible lithium-ion battery. Nano Letters, 2022, 22(23): 9327–9334

118 Qian W , Wang L , Mao X , Yang Y , Yan L , Zeng S , Zhao K , Huang Q , Liu M , Liu X . . Electronic synergy to boost the performance of NiCoP-NWs@FeCoP-NSs anodes for flexible lithium-ion batteries. Nanoscale, 2022, 14(23): 8398–8408

119 Nyamaa O , Seo D H , Lee J S , Jeong H M , Huh S C , Yang J H , Dolgor E , Noh J P . High electrochemical performance silicon thin-film free-standing electrodes based on bucky paper for flexible lithium-ion batteries. Materials, 2021, 14(8): 2053

120 Chen Z , Kim G T , Wang Z , Bresser D , Qin B , Geiger D , Kaiser U , Wang X , Shen Z X , Passerini S . 4-V flexible all-solid-state lithium polymer batteries. Nano Energy, 2019, 64: 103986

121 Wang D , Han C , Mo F , Yang Q , Zhao Y , Li Q , Liang G , Dong B , Zhi C . Energy density issues of flexible energy storage devices. Energy Storage Materials, 2020, 28: 264–292

122 Wu Z , Liu K , Lv C , Zhong S , Wang Q , Liu T , Liu X , Yin Y , Hu Y , Wei D . . Ultrahigh-energy density lithium-ion cable battery based on the carbon-nanotube woven microfilms. Small, 2018, 14(22): 1800414

123 Leijonmarck S , Cornell A , Lindbergh G , Wågbergbc L . Single-paper flexible Li-ion battery cells through a paper-making process based on nano-fibrillated cellulose. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2013, 1(15): 4671–4677

124 Liao X , Shi C , Wang T , Qie B , Chen Y , Yang P , Cheng Q , Zhai H , Chen M , Wang X . . High-energy-density foldable battery enabled by zigzag-like design. Advanced Energy Materials, 2019, 9(4): 1802998

125 Chun S J , Choi E S , Lee E H , Kim J H , Lee S Y , Lee S Y . Eco-friendly cellulose nanofiber paper-derived separator membranes featuring tunable nanoporous network channels for lithium-ion batteries. Journal of Materials Chemistry, 2012, 22(32): 16618–16626

126 Deimede V , Elmasides C . Separators for lithium-ion batteries: a review on the production processes and recent developments. Energy Technology, 2015, 3(5): 453–468

127 Zhu Y , Cao K , Cheng W , Zeng S , Dou S , Chen W , Zhao D , Yu H . A non-newtonian fluidic cellulose-modified glass microfiber separator for flexible lithium-ion batteries. EcoMat, 2021, 3(4): e12126

128 Stephan A M , Nahm K S . Review on composite polymer electrolytes for lithium batteries. Polymer, 2006, 47(16): 5952–5964

129 Xu Q , Kong Q , Liu Z , Zhang J , Wang X , Liu R , Yue L , Cui G . Polydopamine-coated cellulose micro fibrillated membrane as high performance lithium-ion battery separator. RSC Advances, 2014, 4(16): 7845–7850

130 Liu T , Cheng X , Yu H , Zhu H , Peng N , Zheng R , Zhang J , Shui M , Cui Y , Shu J . An overview and future perspectives of aqueous rechargeable polyvalent ion batteries. Energy Storage Materials, 2019, 18: 68–91

131 Alias N , Mohamad A A . Advances of aqueous rechargeable lithium-ion battery: a review. Journal of Power Sources, 2015, 274: 237–251

132 Song W J , Lee S , Song G , Park S . Stretchable aqueous batteries: progress and prospects. ACS Energy Letters, 2019, 4(1): 177–186

133 Zeng X , Hao J , Wang Z , Mao J , Guo Z . Recent progress and perspectives on aqueous Zn-based rechargeable batteries with mild aqueous electrolytes. Energy Storage Materials, 2019, 20: 410–437

134 Peng J , Snyder G J . A figure of merit for flexibility. Science, 2019, 36(6466): 690–691

135 Liu W , Yi C , Li L , Liu S , Gui Q , Ba D , Li Y , Peng D , Liu J . Designing polymer-in-salt electrolyte and fully infiltrated 3D electrode for integrated solid-state lithium batteries. Angewandte Chemie International Edition, 2021, 60(23): 12931–12940

136 Chang J , Huang Q , Zheng Z . A figure of merit for flexible batteries. Joule, 2020, 7(4): 1346–1349

137 Betz J , Bieker G , Meister P , Placke T , Winter M , Schmuch R . Theoretical versus practical energy: a plea for more transparency in the energy calculation of different rechargeable battery systems. Advanced Energy Materials, 2019, 9(6): 1803170

138 Zheng J , Myeong S , Cho W , Yan P , Xiao J , Wang C , Cho J , Zhang J G . Li- and Mn-rich cathode materials: challenges to commercialization. Advanced Energy Materials, 2017, 7(6): 1601284

139 He J , Lu C , Jiang H , Han F , Shi X , Wu J , Wang L , Chen T , Wang J , Zhang Y . . Scalable production of high-performing woven lithium-ion fiber batteries. Nature, 2021, 597(7874): 57–63

140 Ghadi B M , Yuan M , Ardebili H . Stretchable fabric-based LiCoO₂, electrode for lithium ion batteries. Extreme Mechanics Letters, 2019, 32: 32100532

141 Ghadi B M , Hekmatnia B , Fu Q , Ardebili H . Stretchable fabric-based lithium-ion battery. Extreme Mechanics Letters, 2023, 6: 61102026

142 Thakur A , Devi P . Paper-based flexible devices for energy harvesting, conversion, and storage applications: a review. Nano Energy, 2022, 94: 106927

143 Lyu P , Liu X , Qu J , Zhao J , Huo Y , Qu Z , Rao Z . Recent advances of thermal safety of lithium ion battery for energy storage. Energy Storage Materials, 2020, 31: 195–220

144 Parekh M H , Li B , Palanisamy M , Adams T E , Tomar V , Pol V G . In situ thermal runaway detection in lithium-ion batteries with an integrated internal sensor. ACS Applied Energy Materials, 2020, 3(8): 7997–8008

145 Yang S J , Yao N , Jiang F N , Xie J , Sun S Y , Chen X , Yuan H , Cheng X B , Huang J Q , Zhang Q . Thermally stable polymer-rich solid electrolyte interphase for safe lithium metal pouch cells. Angewandte Chemie International Edition, 2022, 61(51): e202214545

146 Ye Y , Chou L Y , Liu Y , Wang H , Kwee L H , Huang W , Wan J , Liu K , Zhou G , Yang Y . . Ultralight and fire-extinguishing current collectors for high-energy and high-safety lithium-ion batteries. Nature Energy, 2020, 5(10): 786–793

147 Wang J , Yamada Y , Sodeyama K , Watanabe E , Takada K , Tateyama Y , Yamada A . Fire-extinguishing organic electrolytes for safe batteries. Nature Energy, 2018, 3(1): 22–29

148 Yang H , Li Q , Guo C , Naveed A , Yang J , Nuli Y , Wang J . Safer lithium-sulfur battery based on nonflammable electrolyte with sulfur composite cathode. Chemical Communications, 2018, 54(33): 4132–4135

149 Li L , Xu C , Chang R , Yang C , Jia C , Wang L , Song J , Li Z , Zhang F , Fang B . . Thermal-responsive, super-strong, ultrathin firewalls for quenching thermal runaway in high-energy battery modules. Energy Storage Materials, 2021, 40: 329–336

150 Malik R . Thermal runaway of lithium-ion batteries without internal short circuit. Joule, 2018, 2(10): 2047–2064

151 Zhang C , Li H , Wang S , Cao Y , Yang H , Ai X , Zhong F . A polyethylene microsphere-coated separator with rapid thermal shutdown function for lithium-ion batteries. Journal of Energy Chemistry, 2020, 44: 33–40