Electrochemical Systems for Renewable Energy Conversion from Salinity and Proton Gradients

Ever-rising energy demand, fossil fuel dependence, and climate issues have harmful consequences to the society. Exploring clean and renewable energy to diversify the world energy matrix has become an urgent matter. Less explored or unexplored renewable energy sources like the salinity and proton gradient energy are an attractive alternative with great energy potential. This paper discusses important electrochemical systems for energy conversion from natural and artificial concentration gradients, namely capacitive mixing (CapMix), mixing entropy batteries (MEB), and neutralization batteries (NB); the working principle and thermodynamic formalism of these systems; and the materials employed in the assembly of these systems.

Keywords:
electrochemical energy conversion and storage; renewable energy; salinity gradient energy; mixing entropy batteries; neutralization batteries

Authorship

William G. Morais

Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-910 Ribeirão Preto-SP, BrazilUniversidade de São PauloBrazilRibeirão Preto, SP, BrazilDepartamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-910 Ribeirão Preto-SP, Brazil

William G. Morais received his Bachelor's degree in Chemistry from Universidade Federal do Rio Grande do Norte (UFRN) in 2010 and his Master's degree from UFRN in 2013. He is currently developing his PhD thesis in Physical Chemistry at Universidade de São Paulo (USP) under guidance of Prof Fritz Huguenin. His research interests are electrochemical systems for energy conversion and storage, and desalination.

Gilberto Lima

Gilberto Limagraduated in Chemistry at the Universidade Federal do Rio Grande do Norte (UFRN, 2013) and completed his MSc at UFRN (2016). Currently he is a PhD student at Universidade de São Paulo (USP) in the Physical Chemistry area under the supervision of Prof Fritz Huguenin. His research focus is on electrochemical systems for harvesting energy in a profitable and sustainable way.

Wellington J. A. S. Gomes

Wellington J. A. S. Gomes graduated in Chemistry (2009) at Faculdade de Filosofia, Ciência e Letras de Ribeirão Preto of Universidade de São Paulo (FFLCRP/USP). He received a Master's degree in Science (2012) and his PhD in Science in 2017 from the same University, working under supervision of Prof Fritz Huguenin. He is currently Professor of Chemistry at the Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP), and has experience in electrochemistry, intercalation electrodes, and electroactive materials applied to the field of electrochemical conversion and storage of energy.

Fritz Huguenin ^**e-mail: fritz@ffclrp.usp.br

Fritz Huguenin is Associate Professor at Faculdade de Filosofia, Ciências e Letras (FFCLRP) of Universidade de São Paulo (USP). He received his Bachelor's degree in Chemistry from Universidade Federal do Rio Grande do Norte (UFRN) in 1996. He developed his PhD thesis in 2003 at Instituto de Química de São Carlos (IQSC/USP). He completed two post-doctoral internships at Instituto de Física de São Carlos (IFSC/USP) in 2004 and at Catalan Institute of Nanoscience and Nanotechnology (ICN2) in 2016. His research involves energy conversion, harvesting, and storage.

*e-mail: fritz@ffclrp.usp.br

William G. Morais received his Bachelor's degree in Chemistry from Universidade Federal do Rio Grande do Norte (UFRN) in 2010 and his Master's degree from UFRN in 2013. He is currently developing his PhD thesis in Physical Chemistry at Universidade de São Paulo (USP) under guidance of Prof Fritz Huguenin. His research interests are electrochemical systems for energy conversion and storage, and desalination.

Gilberto Limagraduated in Chemistry at the Universidade Federal do Rio Grande do Norte (UFRN, 2013) and completed his MSc at UFRN (2016). Currently he is a PhD student at Universidade de São Paulo (USP) in the Physical Chemistry area under the supervision of Prof Fritz Huguenin. His research focus is on electrochemical systems for harvesting energy in a profitable and sustainable way.

Wellington J. A. S. Gomes graduated in Chemistry (2009) at Faculdade de Filosofia, Ciência e Letras de Ribeirão Preto of Universidade de São Paulo (FFLCRP/USP). He received a Master's degree in Science (2012) and his PhD in Science in 2017 from the same University, working under supervision of Prof Fritz Huguenin. He is currently Professor of Chemistry at the Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP), and has experience in electrochemistry, intercalation electrodes, and electroactive materials applied to the field of electrochemical conversion and storage of energy.

Fritz Huguenin is Associate Professor at Faculdade de Filosofia, Ciências e Letras (FFCLRP) of Universidade de São Paulo (USP). He received his Bachelor's degree in Chemistry from Universidade Federal do Rio Grande do Norte (UFRN) in 1996. He developed his PhD thesis in 2003 at Instituto de Química de São Carlos (IQSC/USP). He completed two post-doctoral internships at Instituto de Física de São Carlos (IFSC/USP) in 2004 and at Catalan Institute of Nanoscience and Nanotechnology (ICN2) in 2016. His research involves energy conversion, harvesting, and storage.

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables | Formulas

Figures (12)
Tables (1)
Formulas (19)

pH	0	1	2.2	3.4	4.3	5
w / (kJ mol^-1)	31.167	26.0	12.979	8.219	3.977	1.495
ε_neut	55.84	46.58	23.25	14.73	7.12	2.68
$\frac{w}{C_{b}}$ / (kJ dm³ mol^-2)	1.95	8.67	5.57 × 10²	8.30 × 10³	3.90 × 10⁴	6.01 × 10⁴