80 ISSN (Print): 1844-6116 ISSN (Online): 2501-8795 https://www. jmte.eu Journal of Marine Technology and Environment DOI:10.53464/JMTE.02.2023.13 13 10.53464/JMTE.02.2023… STATE OF THE ART IN BATTERY TECHNOLOGY: INNOVATIONS AND ADVANCEMENTS Nicolae-Silviu POPA 1 , Ciprian POPA 1 , Vlad MOCANU 1 & Larisa-Mihaela POPA 1 1 "Mircea cel Batran" Naval Academy, Faculty of Marine Engineering, Fulgerului Street, no.1, 900218, Constanta, Romania, e-mail nicolaesilviu13@gmail.com Abstract: This paper examines various types of batteries and their modes of operation in a rapidly evolving technological world. From the definition of batteries and the distinction between cells and batteries, to their history and uses in various applications, this study provides a comprehensive overview of the subject. Primary and secondary batteries are explored, with examples such as alkaline and nickel-metal hydride batteries, highlighting the characteristics of each. Additionally, lithium-ion batteries are examined in detail, including their specific properties and innovative mode of operation. The article also addresses charging and discharging methods, including LiFePO4 technology, providing a comprehensive understanding of these essential components in modern devices. Key words: batteries, lithium-ion, operation mode, charging 1. INTRODUCTION A battery is a device that directly converts the chemical energy contained in a drug into electrical energy through an electrochemical redox (oxidation- reduction) reaction. In this type of reaction, the exchange of electrons from one substance to another takes place through an electrical circuit.[1] Although the term battery is often used, the cell is the actual electrochemical unit used to generate or store electrical energy.[2] To understand the difference between a cell and a battery, we should think of a battery as one or more cells arranged in pairs in series, parallel or both, depending on the specified voltage and output capacity.[3] Batteries play a vital role in our lives, providing power to everything from small appliances to cars. They come in various shapes and sizes, each tailored to specific applications and advantages. However, choosing the right type of battery for your needs can sometimes be a perplexing task.[4]–[7] In 1800, Italian physicist Alessandro Volta invented the first battery, marking a significant milestone in battery technology. Since then, battery innovation has been explored and adopted worldwide.[8] A battery functions as a device that stores and releases electrical energy through chemical reactions. It is composed of one or more cells, each containing an electrical charge.[8]  Positive electrode  Negative electrode  Electrolyte When a battery is linked to a circuit, a chemical reaction occurs between the positive and negative electrodes (+ and -). This reaction results in the conversion of expelled chemical energy into electric current.[9], [10] Currently, batteries play a significant role in environmental protection by reducing CO2 emissions, as they have the capacity to store electric energy from renewable energy sources.[11] A major global issue today is the pollution generated by ships, as 80% of worldwide transportation occurs through maritime shipping. A potential solution to mitigate this pollution involves generating electric energy onboard ships using renewable sources and storing it in batteries.[12]–[16] 2. TYPES OF BATTERIES Electrochemical cells and batteries are categorized into two types.[2]  Primary (non-rechargeable)  Secondary (rechargeable) 2.1 Primary batteries: Essential batteries serve as a control source for real devices and gadgets. These include radios, observatories, toys, lights and cameras. It's cheap, easy and convenient to use without a stand.[17]–[19] They are usually round and hollow like alkaline batteries. A critical battery of this type can be a chemical composed of zinc (Zn) and manganese dioxide (MnO2). [4], [20]–[22] Button battery chemistry is also fusible. However, it also contains the chemicals lithium and silver oxide. These connections make this small battery more